The point is that an employer is bound by law to pay you for your notice period. You are obligated to work for that period unless your employer releases you from that obligation (but they still have to pay your notice period). This is the protection part.
This is not true. Where are you getting this from? My last employer used to walk anyone out who left for a competitor and pay the notice period, then they almost went out of business and only started paying through the end of the day. I can't find anything that states they are required to pay you when you're not working anymore.
All seems condemned in the long run to approximate a state akin to Gaussian noise. -- James Martin