You've got a 5v5 game on a single map with a roster of characters to pick. There's just not enough stuff going on. This is a videogame, not Soccer.
The guy is a humongous Soccer fan for reference. When I suggested that simplicity is the best solution to make something enjoyable, his response was roughly:
Yeah, but that's because there's physical and logistic limitations with a ball sports. This is a game being played on computers. We could be making the game do anything! We could be providing options to reshape terrain and create additional cover and constructing new ways to move around. Character matchups aren't interesting enough on their own.
I'll let you take from this whatever you feel like. There's all sorts of interesting stuff you can construct from these ideas.
I sort of agree with him with regards to a single fact: videogames are not the same as physical sports. You aren't bound by the logistics of running a multi-million dollar event where people want to be entertained en masse, want their team/favourite athlete to win and want to yell at umpires. You don't have to prevent injuries, maintain blood rules or do checks for doping. Lots of rules exist in sports for the safety and enjoyment of everyone involved. This need not apply when it comes to playing a videogame with friends.
In other words, I think that videogames can be more enjoyable than sports by being simpler. Like, say, traditional videogame adaptations of existing sports. Take a game like Neo Geo Cup 98 or NBA Jam or Neo Turf Masters. You get the basic objectives of the sport like "put a ball in a gap of some sort", but the similarities often stop there. No people can get hurt or sued for assault, so the games often involve much more fierce rushes to the ball. Much dirtier offense. Much higher scores and much more yelling from the players. There's a certain simple charm in those sorts of videogames that are made just to be played by people.
Does that make something Windjammers or Neo Turf Masters a better competitive game than Starcraft 2? Probably not. Nevertheless, I think that any game should still be fun to play at any level, so having a fun base is a good start.
I cannot even remember what I wanted to write when I started typing. That was 4 hours ago and some silly Skype + Supercade happened in the middle for various reasons. More lucid thoughts tomorrow, methinks.