Whichever one you pick, you'll be learning plenty of lessons that apply in both places. Java and C# have incredibly similar design philosophy, terminology, etc. Both have plenty of jobs available. I'd worry slightly less about choosing based on min-maxing employment opportunities and more toward what feels better and inspires you more.
I've had far less obnoxious people in deadlock compared to Dota. There was some smart decisions to have fewer defined "roles" and less emphasis on having one or a few players pop off with all the resources.
The game itself is so solid, has good balance, the movement and abilities are fun... It's good. Some people are going to get annoying and sweaty in a comparative snowbally team game. I like to thank them for making my games a win-win. Either I get to win the game, or my obnoxious teammate gets to lose.
I too hate the average g*mer but I'm not going to let them steal my enjoyment.