I asked [a question](https://serverfault.com/questions/606281/compact-introductory-overview-of-vpns) looking for pointers to overview materials about VPNs, as opposed to product-specific documentation.  It was very promptly closed as 'off-topic' on the grounds that "Questions seeking product, service, or learning material recommendations are off-topic", with a link to [a post about shopping questions](http://blog.stackoverflow.com/2010/11/qa-is-hard-lets-go-shopping/).

Now, it's clear that shopping questions are largely pointless – they're over-specific and they date quickly – but _all_ of the rationale connected to this 'off-topic' reason is connected with the 'shopping' issue; I can't find any rationale at all about learning materials.  I see that [the relevant FAQ](http://meta.serverfault.com/questions/2330/modifying-the-faq-shopping-edition) initially just mentioned shopping questions, so the 'learning materials' phrase was clearly added later.  Similarly [here](http://meta.serverfault.com/questions/3096/).

The only relevant link I can find is [here](http://meta.serverfault.com/a/5614/160381), which says "we consider education, something all sysadmins should be doing constantly, to be off-topic."  That explanation might need ... a touch more rationale.  I observe that no-one, in the last year, appears to have felt moved to supply the requested explanatory link.

So I'm still rather in the dark.  What's so bad about learning?