Lax concern and slow turnaround for CVEs, poor update performance that led to much of the world turning off automatic updates, and updates being blocked on non-activated installs, if they weren't just easily broken gave root (literally) to fleets of vulnerable internet connected Windows systems being leveraged against the world at large for roughly a decade until Windows 10 brought (and forced) endpoint security practices into the 21th century.
It's reassuring that their official stance hasn't changed; "This is how big we are, and it'd be a real tragedy if we couldn't afford to stop something like what we caused before from happening again...", instead of being sued into responsibility by the world at large.
(Uh oh, not 5 minutes in and it looks like Microsoft PR is already here to downvote the trouble away.)