As someone who tries to cover PSM for
a different site, I don't think you can lay all the blame on Sony.
For one, indies still need to do their own PR. They have to put our press releases, videos on youtube, posts on twitter*, etc. I try to track down news about games, but they have to make it easy to find it.
That really goes back to the Minis days. Developers would put out games and not tell anyone, or release screens or whatnot.
With that said, Sony screwed up the program from the start. It was much too late. They should have started it with the Xperia play, since that seems to be the lowest hardware they are targetting. But it was like 7 months after the Vita launch.
More importantly, they based it around Mono, which seems to be a weird choice. It's sort of close to XNA, but extremely underpowered on the Vita hardware. Reading the official forums, some people benchmark it worse than the PSP in some things. They should have somehow tried to use Unity. That can make commercial quality games.
With that said, having played probably have the PS Mobile titles so far, I don't think most of them really deserve to sell well. Most are closer to flash game quality than mobile. Some remind me more of those games you'd find in magazines, the ones you'd type in your personal computer.
* And don't use PSM on twitter. Like 50 different things use the PSM hashtag, from a French Boy band to a couple different political parties to Pakistani Steel Mills