A whole block? If those would be actual blocks, I am pretty sure that - the whole 'cool, dark and edgy' sillyness aspect aside - it wouldn't look too good. Plus, given how most people die - in a ship torn apart by heavy weapon fire - even fluff-wise, whether there'd be any skull left is very much questionable. I won't even get into the whole thing with player skins and how they affect (or whether they should) the perception of characters, since that's a separate can of worms.
I am not vehemently against it but I personally hardly find it worth the (relatively small but still) effort of making new textures, writing new player death mechanics etc.