Why are you using different words to say you want people to be able to one trick?
Blizzard's stance on this is clear. They want hero switching. One tricking is gimping yourself. No one forces one tricks to one trick.
Solution: Stop being a one trick.
Being a one trick isn't being a "specialist". The people who one trick a hero are never the ones who are best at it. That includes widowmaker, and genji. (Please don't fukin link me any pro. There's not a single pro who doesn't play more than one hero. Shadowburn's pharah used to be arguably as good as his genji. Might still be, but I wouldn't know. There might be a bunch who are only top 5 at one hero, but that's just maining a hero.)
This game needs in depth understanding of every hero, and the best way to understand how to play against a hero with the hero you're playing is to have played that hero. A McCree one trick who's never touched Tracer will never be as good at dueling Tracers as a McCree main who's dabbled with her enough to feel her blink cooldowns, and the damage she puts out based on her spacing.