Same here. I've only played my Hotwire since I got it, so some very fine basses go unsused.
I certainly don't need the others, despite using them occasionally I could more easily borrow or rent, say, a fretless when a studio track calls for it. Live I only bring & use one bass. It makes zero difference in any of my increasingly varied gigs whether I have a P or J or ash or blue or rosewood or expensive or high mass or magic bass/amp/cab/cable/modification. Not to say I don't really enjoy fooling with all that stuff - I do very much, but that's not enough to justify it for me.
I can partly justify it because my bills are paid, I can and do afford whatever I want to do - vacations and such - and I bought nearly all my gear for the same or less than I could/will sell it for, and I've been pretty good about selling more stuff than I buy lately. I've sold old Fenders I loved and some fancy amps, and I don't miss them at all.
But, it's truly a waste. Even if I don't "need" that money, I could be growing it by investing it or doing more patronizing of the arts. I think housing a lot of material posessions is a bit of a character flaw that I'm getting over in time.
People will think I am talking about them, but to be blunt I don't give a #### what other people do with their money. I'm talking about me here, answering the question from my point of view.
I'll read the thread now, as I'm curious to know if anyone else answered similarly. I expect it'd be an unpopular view, which kinda reassures me I'm on the right track. Again, that's how *I* see it in relation to *my* goals in life - one of which is to reduce clutter and not amass it so easily. I'd rather collect lessons and practice time, if anything.