To me, the approach you advocate is something like saying "do away with
law enforcement, force everyone to carry guns, and if anyone suspects
else is committing a crime, they are obliged to shoot them." I believe
spam at its source is far easier than blocking it at every possible
less parties involved in blocking the spam, the higher the probability
that the spam
will be successfully blocked.
To do this you need to form a police force and a judiciary.
Neither are possible in the absence of an organized society.
The first step is for some of the larger senders/receivers
of email to sit down around a table and form an email services
consortium that can set "best current practice" standards and
police those standards. This is something that network operators