It feels useless because in the grand scheme of things, 30 points is fairly negligible.
Also, most jobs just take it all into their main stat.
But there is definitely room for experimentation.

As mentioned VIT can pretty much go on every character. You could make arguments about how non-tanks should be avoiding damage as much as possible, and healers will take care of the rest. You could also argue for tanks putting STR when they're geared up enough to know they can survive without all that extra HP from VIT. But these arguments are for PvE and it's hard to argue against having VIT in PvP. VIT really does help every class against Raw Destruction and Cometeor spam.

There are also other things to try out and experiment that I rarely see talked about. You could put PIE on healers which will help in long fights. You could also put PIE on a BRD to make songs last longer. There is also the problem of the SMN/SCH dilemma where they share the same stat allocation but would benefit from different stats. It's rumoured this will be addressed with the expansion but we haven't been given any specific details about it yet.

Restat item is fairly cheap and stacks to 99 so it's not all that strange to be changing them around every so often.