Wraxu ain't shit, seriously. I have only played seagull "once" so idk. And having high scatter kills is not a bad thing. It's the highest non ult burst dmg
The biggest trick to Hanzo is being commanding. Not like this is my hero kinda commanding, but letting your picks and sonic arrows being known seriously vocal commanding. If you want to play Hanzo that is.
You can play him in comp, you just gotta realize when it doesn't work, and when it works. There's never really a "wrong" pick you are as equal to your parts as a player. So if as you're not answering something as Hanzo, like the 76 or insert hero properly.. You gotta make the decision fast.
The best example I have is, gib, when 76 is holding the high ground with an Ana. I can deal with both of those 30x faster than trying to pick it apart as 76. Albeit widow can do the same thing but with Hanzo, you can continue the brawl with scattering behind rein and just all around dps.
Regardless of where you play, there is a level of understanding that is fucked on both ends. People will always blame the Hanzo. Sometimes it's true, and sometimes it's not.