I don't care what anyone says, but I loved the episode "Deathwish".
Q's whole MO is that he is terrible and rude with people.
I noticed that the episodes tended to revolved more around the humans in TNG, while his VOY episodes tended to focus on him.
Deathwish was good, but Q and the Grey was god awful. If Q only appeared in Deathwish, he would have been handled well in Voyager, its Q and the Grey that really ruined his character.
And as Dream pointed out Q did in the end help Janeway and her crew.
But he enjoyed his wooing and his games before it got to that point the same as he did with Picard.
Heck if I was a Q I'd probably do the same. I'd follow you around Overlord and make quips about your minions and try and make you want me until you wished I never existed.
Except Q was serious at times with Picard, I don't think Q is an completely irresponsible idiot who can't take anything seriously, when stakes were high enough Q rises to the task. If he didn't, he wouldn't have helped Picard in All Good things and Tapestry. The Q destroying themselves with a civil war, there are far bigger stakes then anything before for Q, so him wasting time trying to woo Janeway makes him seem like a childish moron and ignores a lot of the character depth Q has. Q is more then just a trickster, that is the surface, there is more to him then that.