Take what I say with a grain of salt because I play smogon not VGC, but here's my take. I certainly wouldn't call it a bad Pokemon as such, he's UU on Smogon and has a small niche in OU play. But in the VGC environment I don't think he's very viable. He doesn't learn any moves that hit both opposing Pokemon, he's slow and his Special stats are bad. Furthermore, he's weak to Earthquake and Heat Wave. Ouch. Can't even lap up those Defog Defiant boosts because hazards are non-existent in VGC.
I think stick to a singles environment if you want to use Bisharp.