Campaign was fun as a "from time to time" thing, sure. But as a core component of an expansion, as a primary activity? Utterly horrendous. It required no thought, no planning, no responsibility. You just show up and the clock starts running. Granted, it improved on Besieged in many ways but at least Besieged had the decency of being a rare occurrence with real consequences.
Compared to Campaign, regular exp grinding was preferable. You couldn't just throw a bunch of people together and call it a party: you needed a party design, whether "traditional" tank+healer or one of the "burn" style parties, it took some degree of planning to make it work; Campaign required no such planning. It took cooperation and teamwork to make a party function: one person screwing around can get everyone killed; Campaign required no such effort. It had greater rewards and greater consequences in the death penalty; Campaign had no penalty. Campaign was "easymode." It was the easiest of the easy.
I'd rather FFXIV force party play than have it go back to a Campaign model. But I'd rather they fix leves than force party play.
I dislike leves as they are now, but there's no reason they can't be salvaged. Exp grinding needs a major overhaul now too, but there's no reason that can't be salvaged either. I don't want leves to be the main attraction,
as I've said before, but there's no reason to strip them completely from the game.