Really? News to me . . .
My guitar player owns around 20 guitars but only brings his two Teles to gigs, along with a Danelectro he has tuned differently and plays on one song. He absolutely refuses to consider selling any of his other guitars to either a) get a better guitar like a Custom Shop Tele or a Sadowsky or a better amp or even something different like a Club King. He would love to have that stuff but absolutely refuses to consider selling anything to fund it. So he has a collection of guitars he never plays, including some that are rare and valuable but sound like ass and thus are not terribly useful.
I used to have a larger collection (10) myself, but sold off a few of the ones I never gigged to get my ultimate #1. I haven't regretted doing that for a minute, other than the fact that my Revs now get less gigging time, which is kind of a shame.