Yek and Scott hit it IMO.
For me, were I to sell mine, it would be a matter of where I felt my limited budget is best invested. It is not a matter of some dislike of technology, tube snobbery (I own SS stuff, and love one SS amp I have owned for over 20 years), lack of understanding, reluctance to tweak, etc. I look at what I want to express, take inventory, and then try to assemble the most comprehensive tool set I can within my budget. I see new tools, I want to try them. It is not a matter of lack of "ever being happy" or satisfied; I simply love to try new things. New tools (toys) often inspire. I do not use the Axe in front of my amps, so I do use pedals (sometimes). Amps and pedals eat at the budget.
I deleted my original post as I thought it was too negative, a reaction to some of the negativity here I suppose. I am happy with my gear, and look forward to the new soundscapes, gear, ideas, and.. music!!! I look for tools that are comfortable in my hands and head, and new materials with which to express myself. Communities for sharing and constructive critique can be so empowering, and can magnify the usefulness of tools/materials, while providing further inspiration.