Sony realized they were missing out and changed their game play when it was convenient with the PS4 launching.
I've paid full price for both but it's really because I would subscribe for just a month or two at a time to play specific things with friends. Or in the case of PSN, to take advantage of deep discounts like during their crazy Halloween sale a year or two ago. Of course, now I feel ridiculous for not buying the majority of those titles on Steam. They'll disappear within a handful of years from PSN...