The simplest example is that you can’t run Windows without antivirus and firewall, you can with Linux.
That's literally only because there isn't large enough marketshare of Linux to make it worth designing viruses and malware that targets Linux...
As Linux marketshare increases that will change but I guess that point went right over your head.
I really don't think you understand what you're leaving open when you expect a user to be a full-on administrator while connected to the internet and they know fuck-all about networking.