This is pretty much exactly my outlook on it, with the addition of my enjoyment of restoring/refinishing instruments.
Spare money has very little interest to me, but owning and using lots of different basses does.
I can leave my money in the bank and let them make money off it, or tie it up in basses I enjoy and I'll make money off it.
Seems a no brainer to me.
Collecting money seems far more ludicrous to me than collecting basses.
I also don't have any other expensive hobbies, golf, photography, etc. Being in the car trade my whole life has left me bored with them, I buy a car for about £1500, keep it until it's not worth repairing and scrap it, typically around 6 or 7 years, so let's say £225 per year, where lots/most pay that per month for theirs.
The odd thing to me is that society sees spending £30k on an exceptionally speedily depreciating car as the norm, but spending £30k on something like a bass collection as a 'problem'.
You be very hard pushed to spend £30k on basses, to find out in 10 to 15 years time they're only worth £1,500, whereas this is normal for a car.
Obviously there are exceptions to this, as with anything.