Yeah, I'm with the OP on this one. If I understand his logic correctly, I strongly agree with it.
I've reached the same conclusion, regarding the gender, ethnicity, sexual-orientation, weight, etc., of protagonists. Just to use gender as an example -- sure, there are a few exceptions, but the overwhelming majority of films have male protagonists, when you could tell the exact same story with a female protagonist. Imagine Back to The Future, but with a female hero. It'd basically be the same damn movie. Imagine Forrest Gump with a female lead. There's no reason why you couldn't tell basically the same damn story.
John McLain could've been black. Jake Sully could've been black. Kaiser Soze could've been black. But they weren't, because the VAST majority of the time, if the role of the protagonist is not ethnicity-specific, it goes white (as well as being straight male). And I don't think this is simply a matter of casting. Gender, ethnicity, and all sorts of stuff, are written into roles.
But for the most part, non-straight-white-skinny-male protagonists are only written in when the story depends on a specific gender, ethnicity, or whatever, and could not be told with any other. Same is true of minorities.
Some of you have made lists. You've named maybe 12 movies, spanning the course of three decades, that have black protagonists. And most of the movies you've cited couldn't be told with any other ethnicity as lead. And those that could've told the same story with any ethnicity were all Star Vehicles. Will Smith makes any movie he wants to make, because he's a fucking juggernaut.
Of course, this is a money thing. The biggest money-making demographic for major release films is young, straight ,white males. So if you wanna make money, make movies for the people who buy the most tickets. I don't think this is racism, just safe business practice.
That being said, I think it creates a HUGE vacuum for movies that don't put the young-straight-white-male demographic first. I think this is something that could be especially important for us ultra-low-budget folk to keep in mind. Why not fill a niche? If the story you want to tell does not require any specific gender/ethnicity/orientation/etc, why not write the protagonist to be something other than what we're used to seeing?
All of this of course doesn't help with the OPs hope to make a website that streams these kinds of flicks. To that end, Poetrynmoshun, I wish the best for you. To be honest, though, I just can't imagine how a $7000 budget is going to afford you the ability to acquire the rights to many films, or the ability to stream them. Maybe I misunderstood something in your pitch?
Anyway, for what it's worth, I think you could get much more mileage out of a blog. Blogs can start small but grow bit. Aintitcoolnews is now a major force, huge news-source, but they started small. If you created a blog or website that shared news/reviews/etc for the films you want to highlight, I think you could find an audience. Best of luck!