My thoughts have changed as my collection has grown. At first, I didn't care. Then I did start liking to get the boxes more. On some guns (such as my 520, 67, 60, 19's, 15's etc.) I've sold them without boxes and replaced them with boxed examples. I like to get the original box (or what I believe is the original box) though so haven't started collecting "correct" boxes yet - but I'm thinking of getting an unnumbered gold M&P 4" box for my post war transitional, so that could take me down that road.
As others noted, I don't store my guns in the boxes/cases so it does add to the clutter - and the piles of boxes are growing in the gun room. The one exception for me so far has been the pre-29's. I did spring for original boxes for mine - then came to the realization that I'd rather have a new gun or two than that much money tied up in 2 cases with original tools and sold them. I won't get boxes for the pre-29's again unless I just luck into them at the cost of a mahogany presentation box.
All that said, it's not a deal breaker for me - but it is a reason to keep looking after I find something!
Earl