I prefer full share. It just makes sense to me, everything self destructing when you leave seems kinda weird. Yeah in team games it makes sniping a bit less important but sniping all the coms is still the goal. It's more like they have a number of lives, and can be given APM disadvantages as they lose them. Though I usually try to stick around if I die in a team game and mark important structures on the map (nuke, anti, com).
I do feel like it is how FtX said, sniping one guy with a bit of coordination seems to too easily turn into just a roll of the enemy team.