What are you even talking about? People are aware of what hero you've selected; they aren't blind. Why do you think you can only have one of each hero?
Wait, what? Where did I say you should only be allowed one of each hero? Even in the post you directly quoted I mentioned there should be additional
warnings specifically for stacking the same hero. I didn't say it should be disallowed, but I wouldn't be against it.
I don't think people are always aware. I'm well aware they have the ability to check their team composition, but I think people often select their character and start browsing online or sit picking their nose until the game starts. At least I hope this is what what happens since I've been part of so many teams with terribly unbalanced composition. What I'm suggesting is that it should be discouraged, particularly in quick play during the early life of the game imo.
I feel like being able to double up (or more) on characters in the same team makes things less interesting. For example, I'm an mvc fan and I'm glad you couldn't do it (without exploits anyway) there. I think it makes sense here too. Citing current competitive use of double tracers etc doesn't really do much to address what I mentioned. Of course it's going to be used in competitive play if it's not an exploit and it works well with an organised team, people want to win. That doesn't mean that it should necessarily be encouraged going forwards, particularly not in pubs.
Like that team of 6 winstons in this thread. That's a legit win for them. I just think new players seeing things like that will put zero stock in team composition, which could hurt the game going forwards. I mean it must have been flashing up no offense heroes / no defence heroes / no support heroes / too many tanks, and they must have just not cared, so maybe no amount of warnings will make people care. I just feel like character stacking in particular should at least be called out in some way to discourage it.
I'm just spitballing here because imo in the short term I think it's teaching new players that team composition doesn't really matter too much. If the devs intend it to stay like this, then fair enough. I just think that would be a shame because I think it's in matches between diverse teams that this game really shines.