Because there might not have been any "slant" to start with. I'd have to read the originals but from what I've seen so far it's more a "let's blame the left while sticking our ideology into school" move.
Well if the DRM were tripped in a legal game then that would be a buggy mess...
EDIT:
I'm not saying that was the case but a similar thing was done with ARMA II and it had some issues with its Fade DRM system going off when the person was using a legal copy.
That has to be one of the more disgusting things I've read recently. The link to their blog post about it is not working too so here's a functional one.