I do agree that the rant is quite unnecessary.
For what it's worth, the SpamBayes plugin for MS Outlook has reliably trapped at least 99.9% of spam for me for several years now, with essentially no false positives at all (where false positives are defined as legitimate mail that bypasses the Unsure folder by receiving a spam score greater than 90%.)
In practice, this is enough to keep my email account essentially spam-free despite the arrival of over 1,000 spam messages per day.
On the other hand, blacklists accomplish nothing beyond interfering with my own legitimate outgoing email, just because somebody else with a Comcast account happens to be infected by a spam-spewing trojan. Gee, thanks, guys.
As a result, I see blacklists the way some people see unions -- as defensive tools that may have been needed at one time, but that are now just unnecessary, parasitic middlemen.
Firstly, Paul's grand "A Plan for Spam" method of using Bayesian filters to stop all spam ("I think it's possible to stop spam, and that content-based filters are the way to do it."). Uh, so, how'd that work out? Spammers quickly figured out how to make a mockery of Bayes based solutions. And who is still out there filtering spam using IP addresses & domain names? Spamhaus.
Then, what really got his goat was back in 2005 (yes, long grudge holding, one wonders what he feels about the mail-carrier who lost a letter of his back in '78 ;-) when his vanity site, shared-IP-hosted at Viaweb which had become Yahoo! Stores was blocklisted at Spamhaus. Back then, Yahoo, and Yahoo Stores were a spammer-hosting cesspool and Paul's page was wallowing in the center of it. Rather than get to the bottom of it, Paul just got on a high-horse and ranted about the evils of Spamhaus. A good take on the rant can be read here: http://www.circleid.com/posts/we_hate_spam_except_of_course_...
So, multiple biases. How often people forget to mention those when they post attacks. Now one must ask, who is the "bad guy" and is "corrupt" here?
But the Spamhaus people should be happy with the irony in Paul's hypocrisy. How so? Well, his paulgraham.com's email is filtered by Spamhaus, as is his ycombinator.com's email. As are the emails of most of the social/blog sites he's on (posterous.com, etc.) One wonder how many of these still use "A Plan for Spam"? Okay, that was rhetorical.
Lastly, the pop-psychology in his posting attests that Paul's degrees are in philosophy, not psychology.