There are specific tactics and tandem pairs that fight well together in Brawl. It's not meant to be simultaneous duels. Think of a bar fight, your buddy gets punched in the face and you've got a BRAWL. I'm not waiting for him to get up the floor and hit back, I'm jumping in and doing whatever I can to help!
I think it gives Brawls a more interesting and tactical dynamic. I always try to honor the opposing team but I expect it to be 2v2 until someone says otherwise.
I like to stay honorable as long as the opponent is too...
But the most cancerous people in this game is when your teammate don't step in while you get gank....
Sometime they still get gank after... sometime those unhonorable bastard on the others team don't because they know they allready won at this point anyway...
At first I thought this was a cool thing, but as the time progressed, I think this approach to 2v2 is just nonsense. It is 2v2 damn it, not double 1v1. There is a whole mode dedicated to 1v1, it is called DUEL. This one is supposed to be something else. A battle where you have to split your attention to more opponents, but still much less chaotic than 4v4 modes.
Occasionally I go to brawl and propose a real 2v2 before the match. Sometimes the other guys agree and it is a glorious battle. But I respect if everyone else wants double 1v1. Unfortunately the latter case is much more usual. For that reason I rarely ever play Brawl anymore. This approach ruined it for me. I can go to duel instead.