Tbf, if people wanted to run the content synched, you'd see more people running the content synched. I have quite a few synched lv50 EX primal clears and I joined the game in 3.1. Like hell would I farm them synched, though, people are bad and my time is precious.

(Edit: I am also pretty bad, most of the time anyway. Save me from myself)

I'd like to see more incentives for old content, though. (I'm sure someone said you needed ss2 to survive t13's ult at min ilv though, which has since been banned from in combat casts/removed entirely (thanks SB), so there might need to be some tuning to make it doable?) If you put a lockout on min ilv coil that made you have to run it like a current raid, ie in order, and have it drop a mount or something at the end, people would show up briefly. If you increased any kind of reward for regular content, people would be more inclined to run it. The thing is, better drop rates at min ilv compensate for the fact that you can run say ultima ex like five times unsynched in the time it takes to clear it once properly - so I'd damn well hope I was 5x more likely to get a drop.