>- We don't want our private data stolen

>- We don't want a malicious program stealing our electricity and computing resources

>- We don't want adware injecting advertising into our browser toolbar, homepage, email client, etc

>- We want our family to be able to safely use our computers without having to worry about them falling for scams

>- We want peace of mind

Almost all those points are basically the same thing repeated differently:

We don't want somebody else mess with our computer, but that "somebody else" almost always is 3rd party - so not you (user) and not Microsoft (vendor).

Ads from vendor aren't considered as a security issue (unless very edge cases).

They are annoying, but in the principle they aren't security defect (unless badly implemented)