Problem is, we are a fighting a war we already lost. It's put out a
fire here and there, and break a wave while you're at it.
How about seeing some simple measures such as blocking outgoing port
25? at ISP's? Not a perfect solution, but it's a partial solution for
some of the problems. Combined with other solutions we could start
seeing a change.
Blocking ports one by one and filling the Internet by application level
proxies (SMTP gateways for port 25) is not a road worth travelling.