I personally hate mark decon. The main reason being if you want to decon something. Not just move/replace it. E.g. the reac/a turret is going to explode, but i cant decon it. It sucks when its humans, since one building exploding hurts many (e.g. 5) in the vicinity. Now, couple that with rant/sniper spam, and its game over whether you like it or not.
If decon was enabled, then only that ret would be gone, the rest of the base would be fine = less repairing = more building = better chance of survival.