After having hosted countless all welcome games on randomly generated maps I can attest to the fact full share makes the games more fun to play, for both sides. Without it, games end at around 10 minutes, after the first player death, with no chance of recovery for their teammates, after some 2v1 or unfortunate first engagement. This drastic, game-ending outcome often comes as a result of rock-paper-scissors dynamics in the build orders (much more prevalent on random maps), not some grand masterminded strategy that could potentially be scouted and countered in time.
I am, however, dumbfounded by the amount of people that join only to immediately throw a tantrum because they see full share on, then begin to educate me on its shortcomings. Very few games have ended in victory for the team down a player, so the oft repeated argument that full share makes snipes meaningless just doesn't ring true to me. Being down a com and placing more burden on another player does not make the game easier for the losing team, and, at least around my level, it takes time for the the unified economy to compensate for these disadvantages.
I really hope more people give it a chance, and, as funk said, learn to adapt their decision making to this change in rules. Snipe economy, and press the attack once you get a kill instead of zoning out and going sim city.