I'd like to see his hook as a tool to reposition you, getting you from dangerous angles up close to the enemy team. Often you're punished enough, being pulled away from your team (hitbox is very forgiving, too). I think the mechanic of a free kill doesn't suit a tank and being forced to become a observer isn't cool either in any game.
I mean if Widow/McCree get a well timed headshot and kills you, it's that. BAM, dead. Done with it. But getting hooked puts you in that 'passive' mode, watching your death coming straight up. Or being frozen by Mei who has questionable strength, too, because practically no need for reload, freeze AND damage, ice shot with a very forgiving hitbox on enemies (the amount of times I hit enemies with her where I was like 'no way that could hit' and than I play McCree or Widow and be like 'wtf, that was so much of a hit!'; or I see the ice shot flying by in my first person view and still get hit), and an ultimate that freezes within a very short amount of time, through walls and vertically and do damage. On top of that she can heal herself and not only that but block incoming damage while doing so.
No pro genji, tracer or what ever triggers me so often than Roadhog and Mei. Maybe it's not OP and it's totally legit, but it's not fun, however.