SCE made it very clear years ago that they don't care about handheld gaming. You need to look nowhere else than Japan. That's a market where handheld gaming is the dominant format by a significant margin. That's the market where it would've made sense to double down on trying to make Vita a successful platform. That's the market where SCEJA's best selling game in 2015 is Minecraft ... on Vita (which let me add, is their only non-budget reprint physical release on the platform in calendar 2015). That's the market where publishers have been not only able to survive, but thrive off of selling games to as little as 40k-100k consumers. Yet that's the market where the last locally relevant game Sony developed for the platform was announced in 2013. That's despite that game going on to sell over 300,000 copies locally. There's been no attempt to build on that. No low budget projects contracted out to third party studios. There's been literally nothing.
I think you're giving SCEE and SCEA undue praise for localizations on Vita. Outside of a single game, is there any reason to believe they're involved in any of that? They love telling the world they're supporting a series the world has said "no" to five times, so I find it hard to believe they're not willing to pat themselves on the back for translating third party Vita games. XSEED, Atlus, Aksys, Gaijinworks, etc. have been releasing Japanese games long before Vita was around. In fact, most of them supported PSP even when SCE was negligent enough to let some of that platform's biggest releases stay Japan-only. The same can be said for Vita. SCEJA probably translates more third party Vita games into English for sale in Hong Kong/Singapore/Philippines/etc. than SCEE/SCEA do for North America and Europe.