1) I don't think anyone here arguing anti-single player DRM check is actually Pro online gaming DRM checking. Maybe ok with checking against hacks and cheats, but that is different from DRM.
2) You are still missing the point that people do not have an online connection in all cases. I might have online at home with my laptop, but not on the bus, a plane, my parent's house or at my office. If I like to play online at home with my $50 mouse, but play sinle player on the road since I only have the touchpad, the DRM is screwing the pooch there.