I think people are being a little too serious about that devour business. When you're devoured, it's usually NOT just to annoy you. Fact is that devour, if you can hit with it, is the most effective weapon in the Onos' arsenal: It's a one-hit "kill" no matter how much health or armour your target has. Digesting your victim gives you a (paltry) hitpoint regeneration. And it increases the time it takes for your victim to respawn. If I could devour multiple victims, I'd demote gore to an anti-structure weapon. If you think devour is annoying or unfair, complain to the development team, not to the players taking advantage of what they have.
After all, the aliens are the close combatants here. If they can't use devour at will, they lose the best close combat weapon in the game. The second best melee weapon is the shotgun, a weapon exclusive to the humans. Now if THAT ain't unfair, I don't know what is.