It's worth pointing out that in all cases you do still have local copies of the data and binaries required to run these games on your computer, even if your account is locked out of the Steam server. So, despite it being against the EULA (which you're possibly not beholden to after having been banned anyway), and also possibly against your local civil laws, you could always download a crack and continue playing anyway.

You're not "illegally downloading" the games, you're legally downloading someone else's software that just so happens to modify the server authentication aspects of the games of which you once owned the right to store on your hard disk. By running that software you are definitely breaking a EULA that you no longer care about, and you may or may not be breaking laws that you're incredibly unlikely to be caught or prosecuted for.

Your morality may differ, but I don't have a problem with this.