If you did not already think your playing needed improvement surely you would not be wasting money on a teacher?No ones is saying they don't enjoy playing drums. I love drumming. And just like you, I can hardly wait for my next gig.
I'm also not suggesting that teachers tell their students that they suck. I agree, if a teacher told me that all the time, I'd look for another teacher. The take away from this saying is:h if you, the student, can't admit that your playing needs improvement, then I, the teacher, ave no time for you. This is an excellent policy to have, especially if you want to mold great players instead of being "a baby sitter" - to reference another thread.
Encouragement only goes so far. Music is a cut throat industry, where overconfidence is shattered easily, especially if you can't back it up with phenomenal ability. The sooner a serious student can get used to that, the better... If I had a teacher who was overly positive, I would find another teacher, much sooner than if the teacher was a hard ass who told me I sucked.
Without the unbridled ambition to be the best drummer you can, your playing will stagnate and inevitably decline; drumming is a very perishable skill. The greatest players that we idolize had this. Its was their inherent disposition to improve and their ambitious curiosity of the musical unknown that made them the players that they are.
If you are satisfied with being satisfactory, go ahead and be that, to each his own. But while you're sitting around being content, I'll be studying my craft, getting better, faster, and smarter, like many other hungry individuals.