Meh, that creates work for someone that has to clean up the mess. Better to block entirely (with a nice explanatory message) if you’re 100% sure the text is bad, as it is in the “link description here” case, and the UK cabinets URL case…
The goal is to move the burden to the user when possible – even over community approval queues – in these kinds of egregious cases. Users scale, moderators don’t.
That’s true. Plus I’d see your recommendation more for “better/custom validation” than blocking/stopping spam. It seems the Akismet plugin seems to have the next level of spam control under its belt (example: link description here – that’s the only example I can come up with… 
).
This can be a fall back for scenarios where Akismet doesn’t catch it, but I bet that isn’t very many.
I was quickly scanning topics at BBS and was totally expecting this to be spam.
The official Akismet plugin is quite good at catching this sort of manual human spam in our experience. And it is well tested now. Definitely use it!
Minor necro on this, I added a site setting a while back, and it is devilishly effective if used intelligently
auto block first post regex
Case insensitive regex that if passed will cause first post by user to be blocked and sent to approval queue. Example: raging|a[bc]a , will cause all posts containing raging or aba or aca to be blocked. Only applies to first post.
For the next person learning about this for the first time, it’s now auto silence first post regex
Apologies for dragging this into the present after over four years… Also grateful for a tool for addressing persistent astroturfers!