Different POV... how many times a week do you need a given wrench on your bike? For mine, it's zero. You do put in a lot of miles on a tour, but it's going to be really rare to be SO far away from towns and cities that it's impossible to get to a shop. And if you do a quick check over the bike every morning and evening, you'll catch a lot of problems. (in fact, I think our bikes barely hit the wrench every 6 months mark)

So for touring, instead of carrying my regular flat kit of a bus pass, I'd add tire levers, the wrench I need for my wheels, 2-3 inner tubes and a patch kit. I have a foldable Allen key set that works quite well, and I'd take that since it's prudent. Bolts do come loose sometimes. That level of kit will let you handle a pretty wide range of problems, and in a LOT of places, towns are about 20 miles apart or less. So the odds of being so far from a town that you can't walk the bike there are pretty low. Tours are not brevets, so there's no worry about a DNF if you have to walk to town. Mostly, we're not touring in deserts or along the Great Divide trail. So there's no need to bring along the kitchen sink AND the entire contents of the workshop. (no matter how heartbreaking it is to be separated from your toolkit... you don't need the whole damn workshop. really)