"I think the idea is that movies are ungodly costly to make"
This is the part that needs to change. Movies used to be disposable entertainment, which is why people could take some risks with them. Now, you're spending a quarter-billion dollars (can that be right?) on something like Avatar so there's no way you can justify doing something, just to see how it might work out.
"and there's so many other things that people spend their downtime on these days (video games, cable TV, porn), therefore ... built-in audience and they don't have to come up with earth-shattering marketing plans to let people know what it's about."
The other side of that is that is that if you're not trying to build an audience of 300,000 people, you also don't need an earth-shattering marketing plan. If you can make a feature film for $100K - and you can, I've worked on a lot of 'em - then you don't have to sell tickets to the entire world, plus have an earth-shattering DVD release and a HappyMeal® toy tie-in, just to break even. You can't afford stars, but then again you're not beholden to stars.
You're not going through endless development intended to do nothing more than blanderize your writing until it's 'safe' to sell to the entire potential movie-going public. 'Once' didn't succeed in spite of being so inexpensively made, it succeeded BECAUSE it was so inexpensively made. It didn't have to make a lot of money to turn a profit, and if it had tanked completely, the loss wouldn't have been so great - so it was safer to take some creative risks, which resulted in a film that did what other, multi-million dollar films simply couldn't do.
We all spend our days or nights writing spec scripts, that no one's ever going to buy. There's just no real market for them anymore, because the people who'd buy them don't want new or different or interesting; they want bland and predictable and ordinary. Ovum could make one of her scripts into a movie, if she wanted to - raise the money, hire the director and crew, produce the thing herself, and release it as the finished product she wants - not as some watered- down version that's been tweaked according to notes from Jimmy "JJ" "Kid Dy-No-Mite!" Walker and his 'people.' Trouble is, most of the folks who try this approach - and I've worked on a lot of 'em - haven't taken the opportunity to express any kind of personal vision, but have just tried to make cheaper versions of the bland, predictable, and ordinary that H'wood does so well.
If we want better movies, we have to make them, and support them when others make them.
Life Continues, Despite
Evidence to the Contrary
Steven