No they arn't. The vast majority of my mods I have written to fix inconsistencies/annoyances in the games I've been playing (2696 hours according to Steam), some have been intellectual exercises to see if things could be done, and a few have been prompted by suggestions that interested or intrigued me in posts in these (and other) forums. I can count on the fingers of one hand the number of mods I have made because others have directly asked for them. Even the multi-part UI tutorial was an interesting exercise in digging out what gems I could find hidden in the depths of the xml/lua UI code. If nobody played another one of my mods ever again I'd not lose any sleep over it.