I really doubt there is any truth to this. Unless all the other major do, CO isn't.

But I do not think charging for carry on's is all that unreasonable. And I am talking about roller bags - not laptops, purses, etc.

Why should one be able to carry on a roller bag when someone else has to pay to check it (of course Elites excluded).

The Spirit system gives you a choice - you can either check it or carry it on - for the same price - if you pay in advance. If you try to sneak it on - then that is when you get hit for the $45.