I think that it is possible to make a game that people from all walks of life and "demographics" could potentially enjoy, however, maybe that is not to say they will be extremely popular but that they could have a diverse audience.
It is easy to say that the majority of people prefer junk to good stuff but I don't think this is entirely true (maybe only 50% of the time anyway). I think actually though that the majority of people have probably barely seen a movie appealing to their interests that wasn't homogenised garbage for mass audiences in their whole life time and would most likely quite like one if there was one. I guess the reason why they do this to movies is as you said it is designed to appeal to absolutely everyone so it can make more money, and for that reason it must have no distinctive aspects that will turn people off from it and it must be designed to have pointless feel good plot arc that appeals to the lowest natures of each person. The big budgets of many movies also does this but again that is just a monetary decision by the people making the movies. I am kinda exaggerating but something like that.
I don't really design my games with any audience beside myself in mind most of the time. I do generally consider feedback from friends, but I do so in the sense that I consider whether or not I agree with them, rather than thinking of it as "market research". This is not economically feasible and I make no money from making games, so perhaps if people want to make money from making games they cannot operate this way. Actually that raises the question of whether it is better to make games for money or for free.
I try to make games for myself but I constantly want to appeal to what i think people want, and also do the opposite, which then makes this weird mess of a game. also find it hard to steer away from other existing work. I always borrow a lot of ideas from other games but usually have trouble building on them in my own way i think. sometimes i think it's because i forget to face the fact that yes, I am stealing an idea, and I feel like i need to pretend that i'm not, but really I think the game will be better if I just embrace that i am stealing ideas. ummmmmm but I think i'm getting better at not caring too much whether anyone likes what i've done, and putting up with small internet response though I don't make an effort to get much internet response. usually if my mom and dad like what i've done then I am happy