Why was Muhammad (pbuh) buried in Madinah and not Makkah

[Darth Ultor]

Why wasn't he buried in his hometown? Did he have pilgrimages in mind or something? Like if people travel to Makkah, he'd want them to focus solely on God and avoid possible shirk?

[Abz2000]

he was most likely to pass away there anyway:

The thirteenth year saw a greater number of pilgrims from Yathrib; seventy-three men and two women. Secretly, Muhammad contacted the leaders of the group and they agreed to meet at ‘Aqaba during the night on the second day following the pilgrimage. The Muslims of Yathrib kept the meeting secret stealing themselves away under the cover of the night. When they reached ‘Aqaba, men and women ascended the mountain awaiting the arrival of the Prophet.
The Prophet arrived with his uncle ‘Abbas who had not yet converted to Islam. He knew from his nephew that this meeting was to conclude an alliance which might incite Quraysh to a war of aggression as much as it was designed to achieve peace and security. Muhammad had informed his uncle that together with some members of Banu Al Muttalib and Banu Hashim he had agreed with the new group from Yathrib that they would protect him personally. Anxious to strengthen his nephew and people against a war whose losses might fall heavily upon Banu Hashim and Banu Al Muttalib, Abbas sought to make sure that among this group from Yathrib he would find real helpers and allies.
Consequently, he was the first one to open the discussion. He said, “O men from Khazraj, Muhammad’s eminence and prestige among us are known to you. We have protected him even against those of his own people who think as highly of him as we do. Among us, he stands strong and secure. But he insists on joining your party. If you find yourselves capable of fulfilling toward him what you have promised, then you may proceed. But if you would betray him and send him over to his enemies once he has joined your party, you had better now say so and leave him alone.”
After hearing this speech of ‘Abbas, the men from Yathrib said, “We have heard what you said, O ‘Abbas,” and turning to the Prophet, they continued, “O Prophet, speak out and choose for yourself and your Lord what you desire.” Prophet Muhammad, after reciting some verses from the Quran, preached his faith in God in moving terms. He then said to the men from Yathrib, “I covenant with you on the condition that you will protect me against all, just as you would protect your women and children.”
Al Bara said, “We have covenanted with you, O Prophet. By God, we are men of many wars; we are men of the sword, having inherited it from father unto son.” Before Al Bara finished his words, Abu al Haytham said,

“O Prophet, there are pacts between us and some Jews which we are going to denounce.

Should your cause succeed later or among your own tribe,

would you return to them and leave us alone?”

Muhammad smiled and said,
“No! Rather, your blood is my blood and your destruction is my destruction.
You are of me and I am of you.
I shall fight whomsoever you fight and make peace with whomsoever you will make peace.”
The people were about to rise and give covenant to Muhammad when ‘Abbas interrupted and said, “O men of Khazraj! Are you fully aware of what you are about to covenant with this man? You are about to covenant with him to make war against all sorts of men without discrimination. If you have any fear that, should you lose your wealth and should your leaders fall by the sword, you might betray Muhammad, say so now and withdraw from this covenant. For if you do not and then betray your oath, you will have lost in this world as well as the next. But if you feel certain that you can stand by him and fulfil this oath, notwithstanding the loss of your property and the murder of your dear ones, then go ahead and covenant with him. He is, by God, the best gain in this world and in the next.”
All the people present answered together, “We take him despite all threats to property, wealth and life. Tell us, O Prophet, what will be our reward’ if we remain true to this oath?” He answered, “Paradise.” They stretched out their hands to him, and he to them, and the covenant was concluded. Thereafter, the Prophet said, “Elect among yourselves twelve representatives who will be responsible to me regarding your behaviour and conduct.” After they elected nine from Al Khazraj and three from Al Aws, the Prophet addressed them in the following words, “You are the guarantors of your people, just as the disciples were guarantors of theirs before Jesus, Son of Mary. I, for my part, am the guarantor of my people.”
Such was their second covenant which included the words, “We have covenanted to listen and to obey in health and in sickness, in fortune and misfortune, to tell the truth wherever we might be and, at all times, to fear none in the cause of God.”


.................

Abdullah b. Zaid reported that when the Messenger of Allah (may peace be upon him) conquered Hunain he distributed the booty,
and he bestowed upon those whose hearts it was intended to win.
It was conveyed to him (the Holy Prophet) that the Ansar cherished a desire that they should be given (that very portion) which the people (of Quraish) had got.
Upon this the Messenger of Allah (may peace be upon him) stood up and, after having praised Allah and lauded Him, addressed them thus:
0 people of Ansar, did I not find you erring and Allah guided you aright through me,
and (in the state of) being destitute and Allah made you free from want through me,
and in a state of disunity and Allah united you through me,

and they (the Ansar) said: Allah and His Messenger are most benevolent.

He (again) said: Why do you not answer me?

They said: Allah and His Messenger are the most benevolent.

He said, If you wish you should say so and so, and the event (should take) such and such course (and in this connection he made a mention) of so many things.
'Amr is under the impression that he has not been able to remember them.
He (the Holy Prophet) further said:

Don't you feel happy (over this state of affairs) that the people should go away with goats and camels,

and you go to your places along with the Messenger of Allah?

The Ansar are inner garments (more close to me) and (other) people are outer garments.
Had there not been migration, I would have been a man from among the Ansar.
If the people were to tread a valley or a narrow path, I would tread the valley (chosen) by the Ansar or narrow path (trodden) by them.
And you would soon find after me preferences (over you in getting material benefits). So you should show patience till you meet me at the Haud (Cistern of Kauthar).

Recorded in Muslim 2313

[Al-Mufarridun]

From what I heard/read prophets were to be buried at the place they pass away. Prophet Muhammad :saws: passed away in the house of his wife Aisha radhiallahu anha, in medinah, and was buried there.

This is the evident reason. However the point you raised is an intriguing one, it is by Allah's infinite wisdom that he willed Muhammad(saw) passed away in Madinah and not in Makkah.