Caustic is the worst legend teammate to have.

I agree that Caustic should not punish his team, that being said playing with a Bangalore on your team can have the same negative effect. If your Caustic is just mindlessly camping and placing traps yes it sucks. Early last week I started playing as Caustic for the first time and after about a day I found some very useful non traditional ways to use him and he is my new main. 

I don't camp. I will run the map with my team however they want, the one thing with caustic is his traps do stay visible once placed. White outlines can be seen from pretty much anywhere and the mini map shows you where they are as well. Keeping an eye on this will tell you if you have a squad coming in right behind you. Outside of wraiths warning voice which doesn't give you a direction there is no other legend that can revers track enemies. Also if played right in tight situations door blocking could be critical. The only other player that is going to hard charge a door is going to be another Caustic. Revives on fallen team mates throw 2-3 traps fast quick shoot all 3 to detonate and you have a mist surrounding you that does a good job masking you for the revive time. 

My takeaway from this season is all legends can be crappy if played poorly. I have bad games sure, but when a Bangalore or Gibraltar drop their ult on top of me I get just a wee bit agitated. A lifeline that doesn't deploy their heal drone and never drops a care package. Pathfinder grappling out of harms way to watch his team get decimated then not bother to help revive or re-spawn and just puts a zipline somewhere else and disappears. Octane who can just run away and keep on running from his squad or zip in and get all of the loot before you have a chance to start looting yourself. 

Honestly the game is setup for team work and sometimes you have to suffer bad teammates, sometimes not. If someone is going to drop out because I play Caustic so be it. Their decision, it is a public game and I may have to play short handed for this game, but maybe next game get a full squad.