Well with 0 raid completions you couldn't possibly understand the attachment you get to a weapon that you spend hours upon hours and week after week to get. I'm not saying that I keep every raid weapon I get, but soooo many of these guns have their specific uses to make a certain part of a raid a lot easier. Just one example, Pretorian foil, not that good of a fusion rifle overall, but on atheon hard, when you get teleported into a gate, the orical disrupter perk becomes very useful. Also add in a gun like atheons epilogue, a terrible auto rifle, but on a void burn nightfall it becomes epic and untill this week was the only void primary in the game. Start adding in the exotics and some iron banner weapons along with some guns you just want for the crucible and you run out of space really quick. Why should there be a limit to vault space in the first place? So yes more vault space is a big deal.