TLDR: I love when people play weird stuff, it keeps the game interesting. However, if they lock something weird or possibly not as easy to do, I may check their match history and if they are 0-15 on something off meta, at that point it's trolling and their team should just AFK or report them (or dodge if you check before the last lock in).
I think two things are true, it's a game and it should be fun, and also actions speak louder than words.
The first means that you should definitely be able to play what you like rather than what is expected. I played w/ an ADC lulu who was nice, didn't feed in lane, and did just fine. Didn't matter if she did great or not, she didn't do bad and so it would be easy to carry her if need be. In contrast I quit playing adc bc I was so bad at it I was a detriment to my team. That second part is important, maybe it's just because I only play ranked (and bots for fwotd) , but if someone plays something weird, but lets me know how it CAN work, and I can adjust to that so they can succeed, I'm totally happy with that. If they play something that is bad, or they are just bad at and know it, then it makes my game unpleasant because even if I do well, I have to do better than that because I have to counteract some one who is actively playing something they are bad at.
Second, I'll judge things much more on how you play in game than what is expected. If you do great on a weird pick, I'm gonna honor you bc it was different and made my game more fun. If you do terrible I may fuss, I may just ask if you main that and it usually works. If you play something off meta a bunch and have a 20-30% win rate I'm gonna feel justified to AFK and go watch tv or something because you're playing something you know is shitty bc you don't do well w/ it, and I shouldn't have the obligation to play against people who are going to inherently have an advantage against me (since I have a weaker teammate) when I could do something better with my time.