Banning marketing calls and doorstep salesmen would also reduce the capacity for fraud and would cut crime as a result. It is also intimidating for older citizens and annoying for everyone else.
Selling over the phone and on the doorstep in intrusive, invasive and annoying. Why should companies have the right to use your information just to pass on, sell and intrude on your day to day life. Marketing calls come at all times of the day and are more often than not completely useless to the majority of the public.