I hate team coop. It feels like so much pressure. Either I mess up and drag the team down and feel like everyone's mad at me or someone else on the team messes up and despite me playing perfectly we'll lose because of one tard on the team. It makes it really hard to love Splatoon as much as I want to when someone on our team disconnects at the start of the game, at that point we may as well just stand in the corner and do nothing because once that happens you've lost.
I mostly play single player too but if I do play multiplayer it's solo deathmatches and the like, those I have a lot of fun with. I usually do really well in them too, back in the day I used to come first place in every deathmatch in BioShock 2's multiplayer and I had similar success with Unreal Tournament 3. Flak cannon = victory.
Edit: Actually team deathmatch I don't mind as much, thinking about it, since I just have fun killing shit and everyone else is the same. But with team games that need strategy I nope right out of there.