It's bad for the company when all the small annoying timesinks eventually add up to become a big enough annoyance for the player to quit. Additionally, it is bad for the player long before that point.
In reality though, it doesn't make players play the game more, because a lot of them will just screw it all and not bother with the piece at all if they can't make room for it.
Take me as an example, I will gladly spend time on getting the +2 pieces that are good at +2 and that I will use regularly. However, the +2 pieces that are very situational and do not offer a very good augmented buffs, I will simply not get at all. Not the +2, and not the augmented +2.
In this situation, it is easy to see that I actually play less, not more, because if I could have stored the +2 right away, I might have taken it to that point and stored whenever I needed the space. Currently, if I take it to +2 for "fun", I would have to throw it away if I needed the space. While I would spend 500k for a piece just for fun, I would not spend 500k on a piece I would have to throw away later because I needed more space.