> because it would be less work for them or otherwise advance their own personal interests

I've seen plenty of people rationalize not wanting to learn a new thing with those words.

The thing is, this is a rationalization too. It may be true, it may also be false. The only certain thing is that they don't want to learn a new thing.

That said, this happens in small circles, where you know the context of the person asking the question. People assuming they know why a stranger is asking something tend to be wrong too.