I think alot of us hobbyist & enthusiasts only need what satisfies the pleasure centers of our brains, and that craving will always change. If one can make a case for a certain camera or format because of this or that, it's generally a self willed desire. Pro's on the other hand obviously need the right tool that accomplishes the task with a minimum of effort/ability to satisfy a clients needs or their own production for sales.
95% of my stuff is on the computer. The rest sits in a drawer comprising negs or prints and there is only a handful of images on my wall. I email images to my friends and family that I have taken. What the hell do I need a 4x5 or 6x6 for? One day I"ll get a Jones for a different format, buy it, and nothing else will change except what neg pages I need. If it ain't useful sell it and buy oil stock.