I think that people will get used to the idea over time but overall I believe people get very frustrated with each other thinking that they are supporting the team the best. Ultimately it comes down to not always just picking your "Go to" hero and instead playing what your team needs to just get that extra push on an objective, or to prevent them from pushing you.
Overall I think the game is good, but until people begin to understand this it's hard to recommend this game to people who really don't have a couple friends to play with consistently.