This is a fair point. Once again it's the game's lack of development - I was constantly expecting the "creature comforts" type stuff to have some other effect like strengthening Eidolons or making Chocobos avoid enemies more easily. So I didn't use them. Only to find that they would've been suitable for a small part of the weapons upgrades.... only!
Because hitting x on hundreds of components individually to see what they're worth in weapon exp is just sooooo much fun. Almost as much fun as buying 99 HEALs in FF1.