It's not even that he "took" them. The Elite decided to bet on themselves and start a new promotion. That's why I think it's relevant to make the distinction that it was ROH's top drawing acts that went "we can do bigger and better" and starter their own shyt. Sure, they got the money guy, but it's wrestling 101, you don't get a big national promotion without the drawing acts to make it sustainable at the start, and you need those wrestlers to make the jump.
It's not necessarily the norm in the U.S but it's pretty common in Japan.