The other big reason that they aren't allowing legacy trophies, is that since the original launch of the trophy system there has been an exploit to unlock trophies without doing anything in game. This was the problem that came up when they did those trophy based giveaways years ago. Legit players had almost no chance to win because people were literally creating new accounts, running the exploit and entering the giveaways with their freshly exploited 300+ platinum trophies. On top of that, one of their engineers said it was nearly impossible to tell real trophies apart from the exploited ones with their current system in place (something that hadn't really been updated since they launched on the PS3). So patching the exploit and starting from 0 from this date onward was probably the only option they could get greenlit. They still haven't updated their archaic implementation of PSN accounts, so I don't see them really wanting to put money towards making a system where a computer runs a logic script to compare everyone's trophies to the date and time that they were received and the estimated times in between those trophies that should be realistically possible. Not to mention how many times Trophies and Achievements both have glitched and either accidentally awarded them all at one time or when they didn't award them at all.