Assalamu Alaikum
Would you marry a very extremely physically unattractive with the hopes that she will become your dream girl? The reality is you probably will never even come NEAR a woman like that.
The same reasoning applies to why some women will not marry a man who has no money, job, home, etc. The reality is BEFORE marriage, there is absolutely no time wasted on anyone, no sacrifices made, no emotional bond, no commitments, and no experience to know any differently than what they were brought up in. So women have their views on what marriage would look like to them, and they have the exclusive right (same as men), to keep their options open and wait for someone who has all those things they desire. Why should a girl who lives happily with her family, and has everything taken care of, choose a life which is less than? This is a valid question. You have to present something which is far greater than what she already has and I don't mean just materialistically. You also need to take in account that a man can see a woman and know immediately by physical appearance whether or not he will propose to her or if he will be interested. If she's not physically attractive AT ALL, regardless of her personalities and other qualities, would he even think about her? Probably not. So in that aspect, that is where we are equal. Is it a man's responsibility to ask as many of the unattractive women he knows for their hand in marriage?

Nope. So as women it's not our responsibility to accept every guys proposal if there's a chance there's a better one coming along.
Now for your actual question, how come your mind jumps to divorce? How does divorce help you if your issue is to get married to prevent fitnah and fulfill the feelings you have? You'll just be starting from square 1 again. Divorce isn't a solution to anything unless if being divorced prevents you from a great fitnah or say, Allah forbid, the wife cheated on you or commits kufr. Those are VALID reasons. After marriage, there is the hope that you will build some sort of life together, gain experience, have an emotional connection, attraction etc. so there's much more on the table there with divorce than there is when presenting yourself for marriage. If those things are absolutely non-existent, then sure, get divorced. If her beauty is what's keeping you there, then you probably shouldn't get married to begin with because it's inevitable that we all lose beauty in the end. Both men and women have this fear for divorce, that when they get married, this is the notion that they build their marriage upon. Marriage has to be build on longevity, and as Muslims we know what lasts and what doesn't. Maybe that's the point you're trying to make with your question but we need those initial things that "hooks" us to each other, however what keeps it going are the everlasting substances far beyond those superficial things.
Your mom's reply is kind of a generalization though. I personally don't believe it's important for a man to have a college degree, but he should be educated, smart, intellectual. I don't believe he needs to be wealthy, but he should be financially stable and hardworking to never need the help of anyone else. Why's that important? Because I'm your responsibility now. If another man needs to help you, I should've just married him

. He doesn't need to be a model, but I gotta tolerate your face in the morning and laugh with you ;D You don't have to have a house, but I don't want to live with your parents. You are a college student, and I am as well? We can work upward and go forward together and build our future together. Get the point? You need to give an alternative to what you don't have, otherwise if you're just like "accept me as I am and be hopeful" it's not going to fly. They don't know who you are. You are a list of facts, so there's nothing there to build the hope on.
You deserve a chance, even if she won't like you..you deserve to get to a point where you can meet a girl and see her face to face because we are Muslims and our trust is in Allah subhanahu wa ta'ala in the end. With everything I've said, in the end a girl can throw all of that out the window because Allah opens her heart and she meets someone who is worth more than the superficial, generalized, stereotypical descriptions of what her husband should be, simply because Allah destined her to be with this man. He wrote their names together before the world was created. And in some crazy fashion, their pathways to marriage is made easy despite all of the odds against them. Maybe explain that to your mom and let her BELIEVE IN YOU. A lot of times moms can tell when their son is mature enough to be with someone and sometimes they just dont think he's mature, hardworking, or feel reassured about you caring for someone else, etc. They should STILL try, but you should also try harder to convince her that you have qualities she will be extremely proud to brag about to others
I don't want brothers to lose hope and grow bitter just because it's not working out. There's a reason his wife is not there yet, but you have to be proactive as well in all other aspects of your life. Hypothetical questions can give us some insight and be helpful, but they are no where near reality because we each have a fate written for us and it often includes events we can never predict for ourselves.
SHORT ANSWER TO YOUR QUESTION: NO, it's NOT fair.