Robert Hanlon himself doesn't seem to be notable in any area of rationalist or scientific philosophy. The most I could find about him online is that he allegedly wrote a joke book related to Murphy's laws. Over time, it appears this obscure statement from that book was appended with Razor and it gained respectability as some kind of a rationalist axiom. Nowhere is it explained why this Razor needs to be an axiom. It doesn't encourage the need to reason, examine any evidence, or examine any probabilities. Bayesian reasoning? Priors? What the hell are those? Just say "Hanlon's Razor" and nothing more needs to be said. Nothing needs to be examined.
The FS blog also cops out on this lazy shortcut by saying this:
> The default is to assume no malice and forgive everything. But if malice is confirmed, be ruthless.
No conditions. No examination of data. Just an absolute assumption of no malice. How can malice ever be confirmed in most cases? Malicious people don't explain all their deeds so we can "be ruthless."
We live in a probabilistic world but this Razor blindly says always assume the probability of malice is zero, until using some magical leap of reasoning that must not involve assuming any malice whatsoever anywhere in the chain of reasoning (because Hanlon's Razor!), this probability of malice magically jumps to one, after which we must "become ruthless." I find it all quite silly.