Well seeing as there’s been 1,000,000 threads starting with almost identical posts, yes I think there is enough interest in it.
Unless things maybe go down the route of 26 for downhill, 27.5 for all mountain, and 29er for XC and marathon racing. Cant see it happening though, all the faffing around and having 3 bikes where barely any parts are interchangeable if you need to grab say a wheel off a different bike as an emergency fix.
You’re right, 29er for everything is a much better idea. Dirt even did a test, a 29er 4″ bike was faster than a 26er 5″ bike, a 29er 5″ bike was faster than a 26er 6″ bike.
I reckon we’ll see 26ers like we do hardtails now in 5-6 years. You’ll tell everyone they should have one to make them a better rider, learn skills, etc etc etc, but when you go out to the shed you’ll pick up the FSer 95% of the time.