Smash is a party game, yes. The point of Smash is to goof off. However, Smash has for all intents and purposes been hijacked by the community as one of the biggest competitive games in the FGC (Fighting Game Community). This forum board is a product of the competitive Smash scene. Coming to us to complain about people playing in the competitive format in 'Elite Smash' (the bracket where the developers thought to keep us during online play) and using the rule set that the majority of us utilize is like complaining to a Chess Grandmasters community to why they don't play Checkers and then insulting them.
Your salt levels are on you. What you perceive as the community "try harding" is actually probably average competitive players trying to get better as there is no real complaint within the community about "try harding." We practice, lab, compete, and practice even more to make those 'try hard' moments something consistent so we can do better at tournaments. If you dislike it so much, then you have four viable options that I see.
1. Join the community rather than hate on us, and get better and start winning.
2. As R208 said, wait for a bit to have your GSP (rating) to go down and rejoin the casual scene.
3. Stay local, and play with your friends only and stop playing online.
4. Stop playing in general and let the hate consume you and not affect us at all.
As for my own opinion, I'd prefer you take option 1. I love having new eyes and new people in the game who genuinely want to get better. It makes us a bigger and better thing as long as you contribute positively. However, you can't just attack a community just because you're not good at the game.
Anyways, I hope this helped. Don't let your losses affect you personally, grow and learn from them.
EDIT: Spelling.