True Hinduism is actual very monotheistic, but discriminative people like to associate it as a polytheistic faith, because they cannot understand it with all the different sects that there are.
But you have to remember Hinduism has been around for like five thousand years and during that time there have been many alterations and divisions. The Hinduism we see today might be far different than the one that existed during the Aryan invasion over India.
So of course there are going to be huge divisions within the religion.
But anyways Hinduism comes from a mixture Jainism, tribalism, and a faith brought over distictively by the Aryan invaders (probably Abraham's version of Judiasm).
Ancient Jainism is super old in religious terms. Jainism could be considered as humanity's first religion. But the common use is very different from the ancient variety. Present day Jainism is very similar to Buddhism, but the ancient variety was probably crafted by Krishna as he existed well before Hinduism and the Aryan invasion that led to the establishment of Hinduism.
Nevertheless, Hinduism is a monotheistic religion that takes into god in a diverse fashion as that of Abrahamic faiths (with the exception of certain sects of Christianity).
You see in Islam, Orthodox Christianity, and in Judaism, God is shapeless and does not have a shape at all.
But in Hinduism, god is shapeful and has an infinite number of shapes. And if it wasn't for this citation of god, we would never have come up with the number (zero), which stands for nothing.
So technically Hinduism is no different than most other faiths. It just has god with a hundred diverse forms that each have there own idol.
But then I guess people don't understand why they make idols in the first place.
Hindus and Buddhists (which also have their own idols) make idols in the same sense that Jews and Muslims discourage idols.
It is like that Mexican General that fought for Spain and Mexico during Mexico's war of independence.
So technically god didn't discouraged Hinduism and Buddhism, because they don't abuse their idol worship in the same regards as that of Pre-Islam Arabs.
Maybe god punished the Pre-Islam Arabs, because they abused their idolism and as of such. God forbid them to ever have any idols.
Does anyone remember reading from the Torah, Bible, or Koran about Moses and the ten commandments? When Moses can back down from the sacred mount, he discovered his people bathing themselves in foolish idol worship. (not in the same regards as that of Hindus and Buddhists). As someone who knows god extremely well, I do know for a fact that the hebrews were punished because they abused their idolship to the point of going against god.
However, Hindus worship their creator with idols rather than going against him. So they weren't punished and allowed by god to continue their idolship. Because it is just the idolship of god under an infinity of different forms. Technically that is no different than having god worshiped with any idols at all. If you can recall infinity = zero as both being non-real numbers. Otherwise, because I know god would very well have sent a prophet over to clean up that mess. But it probably isn't really a mess at all, just to those that share eyes of envy and disconsent. Like why should Abu-whatever be allowed to worship an infinite number of idols of god, when Jin-whatever cannot, because he's a muslim or a jew.
This isn't in any means of encouraging people to take up any faith. This is just providing you with the insight of why the Hindus are never punished by god for their idolship.
But they were punished nevertheless for their power hold over their own people which is shown to be quite similar to that of Pre-Islam Arabs. You see, Pre-Islam Arabs used idols to control their people and benefit off of them. Much in the same way the caste-system was used by the Hindus over their own people.
Furthermore, Catholics were never punished for their idolship of god either until after the crusades because they started to abuse that religion and turned away from god, which is how Martin Luther became a prophet.
God had punished them for that wicked deed by sending in Buddha to bring them away from that. Buddhists share the same religious context of idolship, which is why they are never punished either. Future prophets would only come about to bring back the order that was lost as past prophets went their way in afterlife.
That's how the Bahai'i faith, mormonism, protestantism, evangelicanism, Tenrikyo, Cao Dai, Sikhism, and Unitarian Universalism was established.
Old faiths are being renewed by new prophets. And this will continue forever and ever and ever as long as god and humanity co-exist, which is forever hopefully.