The only steam related issue I recall coming up was people throwing fits about not wanting to use steam.

The only issue's I've experienced in game were caused by DDoS attacks causing server stability issues and having to wait in a login queue when an expansion launches or has a major update. Though it has been popping up regularly with a login queue of 20-30 people when I log in outside those times ever since they started that world visit system thing...

That basically feels like coming home and having some person visiting your neighbor parked in your driveway that shouldn't be there. However I cant just park behind them and box them in and then refuse to move my vehicle when they want to leave later since its an online video game...