Forgot to add the line count of backdoors and stupid absurd shit like processing fonts on the kernel rather than userland so people can hack your 896 core machine and mine bitcoin.
Your claim of backdoors is nonsense of course, but the kernel mode font handling was indeed a security risk. However on recent releases of Windows, they changed font parsing to run in a user mode sandbox: see the "Mitigating font exploits with AppContainer" section of https://cloudblogs.microsoft.com/microsoftsecure/2017/01/13/...