Indie games simply don't matter very much in the big picture. They are not a system seller. You can get them on most platforms, some people enjoy them but they're not enough of a big deal so that Sony would want to pour their marketing millions into them. Heck, sometimes it feels like they don't even put their full marketing weight behind their AAA exclusives either. Besides, word of mouth and users on the internet are doing very much of the marketing nowadays.