their games protected to maximise their revenue
I never heard of a game that sold better, because it had copy protection.
The thing is, drm only ever hurts legitimate buyers. The non buyers just download the hacked drm free version. While the legitimitate buyers have to deal with broken files, inaccessible drm servers, lower performance and whatnot.
Also, the protections that do protect a little are the ones that will hurt the user's systems the most. And that little is only a time window of a few weeks, till it is hacked. And for that, the publisher has to dish out a lot of money to license the copy protection.
So, if the goal is to maximize profit, I say, that calculation is wrong. They could save the license money for the drm and sell some more games to people that avoid certain drm out of principle.