The excuse is BS. Microsoft is the cause, by allowing crapware to be bundled in the first place
MS doesn't control what H/W manufacturers package with the OS. For be signature compliant they need to follow rules MS put in place.
Also, other OSes manage to get better hardware compatibility out of the box without Microsoft's massive labour force or playing around with drivers suddenly not working
That statement isn't clear to me. I don't know if your saying other OSes come with better h/w support than MS or the other way around. I'd like to know which other OSes you speak of because last I checked MAC OS didn't have any driver support beyond their own h/w. As for Linux, they have barebone hardware support which MS pretty much matches.
At first, Linux distributions just weren't easy to install for everyday end users. Today, that isn't true. However, most of the Linux support is still handled by the community and there is no accountability by any given entity. Dell, HP and company would love to put a free OS on their H/W but they don't want to handle OS issues because it now becomes their responsibility.