Well, with regen health people aren't afraid to actually push for map control. I find this all the time in games like Counter Strike where people will sit behind a crate and put off pot shots across or down a hallway at random with the intention of just taking off 10% of someones health to put them at a disadvantage. It would be horrible to play Gears and have 20% of your health gone right off spawn because some guy is taking potshots with a pistol.That seems like a really strange conclusion to reach when regenerating health basically keeps both parties safe as long as they camp. If there's a timer counting down the match's time, once a team gets a kill they're in a good position to camp and if there is no timer it's stale mate city and at that point it's just down to who isn't feeling patient.
A shooter's "campiness" is imo driven far more by the actual objectives in the match than anything else.