The trouble with zero RB is that it relies on several things.
One - All the first/second round RBs being shit/getting injured. OK, that largely happened last year, but Johnson, Elliott, McCoy, Freeman and Bell have more or less held entire teams together this year.
Two - RB replacements being more or less as valuable as the original. Patently not the case, see E Elliott/A Morris, D Johnson/A Ellington.
Three - Picking up the replacement RBs on the waiver wire when players do go down. This is fine, assuming all the other owners have given up or are dribbling vegetables.
On top of all that, in most cases there is only one RB worth having on each team (and in some cases zero, thanks Giants), while there can be two or three receivers that are valuable on any one team. Fuck’s sake, Pryor and Coleman have been useful for fantasy purposes on an 0-12 Browns team. So the pool of RBs is so small compared to WRs, as you allude to.
There’s also absolutely no guarantee your elite WRs will perform better or remain injury free compared to their RB counterpart. Take Amari Pooper’s first 4 picks this year: Hopkins, Robinson, Cobb, Decker. Why, is that a 2-10 start I see? Yes, yes it is.