you mean people actually use it on purpose!? 

I guess it might be the sort of thing that is maybe tempting to use in an enterprise environment if you haven't understood how it works and the resulting risks.

Fortunately I learned with "service provider mindset" as we acquired a SP network with some Cisco in it ~20 years ago and when I took the cisco press books on holiday to learn how to run my new network, the immediate determination on VTP was: "no, never that"