Few are as scrupulous about maintenance as I and the one time this year I needed a multi tool had nothing to do with maintenance.
A stick jammed into the spokes and pulled the rear wheel into the chainstay. Wabi wheels use a 5 mm Allen bolt. I left my saddle bag at home that day and walked four miles until another rider came along.
People are free to carry or not carry whatever they feel is right. I don't think a basic multi tool is extraneous at all.
The
Fabric 16 is $25 and weighs 110 grams. I own four. None of them did me any good that day but I'm still glad I have it with me even if I don't use it.
-Tim-