The extraction problems with steel cases stem from carbon blow back since steel cases do not expand as much as brass cases. Therefore the gas sealing properties are worse. The coating of the steel cases is reducing shell adhesion and friction and there isn't that much stress on the extractor until, or unless a brass case is fired after a lot of steel cases being shot without cleaning the chamber. The expanding brass case will then adhere to the carbon deposits and extraction will be harder.

That said, I have no problem with shooting cheap steel cased ammo in some of my cheap ARs and Glocks, especially in rapid fire sessions.