I think my only bad experience so far was the Moogle boss fight. I really really hate when people try to tell me what to do. Like you can suggest, you can say "hey, we should do this as a plan". But if you immediately start with the orders... and try to tell me how to play as a superior elitest? Yeah no. I don't take orders. -_-.
There's a difference between being a leader to help, and commanding like you're a drill sergeant. Other players aren't your army.
Also, I have my own play style, rather than the complicated charts and diagrams others use. I play my class with what works for me.
The only other times were some parties uncoordinated. But I chalked it up to being new, or unfamiliar and just tried my best to help.