The point of Deadeye isn't to kill people. The point is to zone, create pressure, and put your team in the best possible set up to start or win a fight. When Deadeye does actually get kills, those kills tend to be /huge/ since they basically start the fight. Also in a lot of situations where McCree ult wins fights are situations where Soldier's ult would have done nothing. They are so drastically different in function it's not even funny.
I get in random ladder soloq matches it's easier to jump into a poorly organized fight and mash Q with Soldier. That doesn't take away the fact that a set up Deadeye (which yes does happen in solo q and not just pro games since it just requires a shield and a support) is still really good. Hell it's so good that it gets Nanoboosted. Nanoboosted Deadeye is such a common combo that there's a casting nickname for it (Electric Cowboy).
