Valid enough, but 20 is better than 100.The biggest iPhone compatible carriers do not have and have moved away from unlimited data. TMobile offering unlimited data has not brought unlimited data to iphone users on AT&T or Verizon, in fact they have moved away from it.
Does it help consumers in general, yes. Does that help Apple? Not directly and only marginally at best. They seem to sell iPhones pretty well regardless of how the carriers screw their customers.