Yet 90%+ (?) of players/matches are not 1v1 so surely they are in fact more important.
Yes, for Relic's catering to the needs of the community, but not for "this is op and nerf that and this is a stupid interaction" whining in balance threads. Everything gets derailed the more players take part in it. The game and its little interactions are very complex, there is no solution to please 1v1 and 4v4 players alike.
As I mentioned before, they should simply add a disclaimer to loading screens beyond 1v1 tellin ppl that there may be imbalances and increased numbers of weird interactions since more than 2 ppl are playing.