pretty sure there's some sponsorship from a bike company pushing plus bikes in those "reviews"
I'm running just about every size tire at the moment, yeah I'm one of those guys....
And yes, my fatbike will be faster in 6" of fresh snow than my XC bike with skinny 2.35 tires.
I personally don't like 27.5+ tires, but lots of people swear by them but I'll never tell them a 29 wheel is better