Ayup.
I got a new computer, and never reinstalled LoL partly on account of shitheads...but mostly because my router hates LoL for completely unknown reasons. (I did not have this problem with any other game, or to this severity. It's so weird.)
The LoL community (pretty much every MOBA I've played, in fact) is full of shitheads, top to bottom.
At the bottom, you have stupid shitheads, and trolling shitheads who think throwing games is hilarious.
In the middle ranks, you have pretentious wannabe-pro shitheads.
At the top, you have condescending shitheads.
If you want to compete, prepare to deal with ENDLESS hordes of shitheads; you'll probably become a shithead yourself without even noticing.
If the stars align, you may find good teammates who will actually practice with you, and accept both success and failure somewhat objectively. Those people are the ones who break out of "ELO Hell".
On the other hand, if you aren't doing Ranked, and just play for the sake of playing, I won't judge (nor should anyone).
If it's for fun, it's for fun. "Professionalism" really has no place there.