I have two problems with this. First, it's just an ignorant statement. Upthread several of us noted that there are cycling specific shoes that are not clipless. They work great. Some of us like them as much or more than clipless shoes when we're touring and we are actually able to climb hills with them and spin at a 90+ RPM.

Second, I think you may be a victim of advertising. Bike touring is not a criterium, stage race or brevet. It's touring, the cycling equivalent of sauntering (and, yes, I've done 150+ mile days, and I enjoyed those, but if every day is about pushing I'm cheating myself). There are people who come to this subforum excited to get out. Many posters rightly tell them to grab a bike and ride, but many others try to convince them they need many thousands of dollars for a bike, the best "kit" off the hangers and all kinds of doodads that the internet pushes at us or they'll end up in a fetal position at the side of the road or crumpled at the base of a hill their lousy shoes refuse to attack.

Clipless pedals are great. Flats are great. They both work well. I prefer the former on my road bike. I prefer the latter for singletrack, touring, commuting and fatbiking.