You say "unneeded", but I couldn't disagree any further with you. Each and every character can do well, even in situations that they generally aren't exceeding at - for instance, the other day I was playing against a Symmetra on attack on Route 66, and her teleporter and ruthless chasing down of our Tracer and healer was what basically carried that team to victory.
It mostly depends on what the player using that character does. If your Symmetra is good at being Symmetra, let her be Symmetra and don't yell at her to switch to a character they might be worse at playing. Even in competitive play, I'd rather have a competent Symmetra on a map that's not favouring her than her switching to Pharah and just doing fuck all or worse, feeding.
Now if the Symmetra was shit, sure, feel free to complain. But there's a good chance they might've done just as badly or worse with a different hero.
