You said it yourself "malware" but it's crap at it's job so best off disabled and install something of merit.
And I think you are trying to dodge my point, which I am sure you saw.
Windows Defender is doing something other than being an anti-spyware product. You've just admitted that yourself.
Now when we start to define "malware" we are expanding the field considerably.
So the question stands -- what other malware is Windows Defender blocking?
By the way, your personal opinion as to the merit of a security product is off-topic here. I am not asking anyone for their views on which anti-virus, anti-spyware, and/or anti-malware product is better than another.