I played with them though. I'm not going to waste my time, have less fun, and perform worse becoming okay with 20 characters when I can have a ton of fun and perform extremely well becoming great as 1. Maybe one of the future characters can grab me, but what obligation do I have to use multiple characters when everyone is better off with me just playing one?
I like that you conveniently switched your argument for only using Soldier 76 because you liked him the best, to well I'm not good at anyone else and therefore would be a detriment to the team.
Either way, it's clear have no desire to maximize your team's effectiveness in a team based game. That's fine. However don't go scratching your head wondering why your team lost after hitting tab and seeing no healer or tank.