But nobody is using iPads as a sole production tool. It's part of the production tooling but it's not exactly an essential part or a part that can't get rid of or replace easily, unlike a "real" computer.

It's rather disingenuous to pretend that an iPad can be sufficient. At its price tag it is still a rather extremely expensive accessory and people pretending otherwise are just full of it. There are enough reviews/testimonies saying as much (even from the diehard fans) for it to be an obvious fact.