Basically people don't bother to research and optimise their rotations. I've seen all sorts of crap including:

- BLMs who spam Fire III > Transpose > DO nothing until full MP > Repeat (Quite a few of these actually)
- SMNs who let DoTs fall off for up to a minute at a time
- SMNs who don't use DoTs at all
- MNKs who just stay on one direction and don't switch between flank/rear at all. Might have worked somewhat in 2.0, not anymore.
- MNKs who constantly let GL fall off, even on bosses which stand still the entire fight
- A DRG who used nothing but Full Thrust over and over
- Actually DRGs in general, they're almost all terrible
- Probably loads more I can't recall

A lot of these people have managed to scrape through some of the endgame content just by overgearing it and being carried by others, but I get the feeling they're in for a grim couple of months wiping horribly to Twintania (even with the echo buff) trying to even get to try Turn 6 (which they can't overgear).