Isn't there even a bigger scenario.

Airlines the world over, would like to see the end of "checked bags".
When you think about the cost involved in transporting your bag - checking it, transporting it, returning it to you. Mega, just mega cost, all that equipment, all those people, all that weight.

Roller aboard is the desired outcome, specially for the clients that are leapfrogging from country to country (chasing low cost fare options or adding award segments) and multipling the "bag handling" cost factor.