You are not going to see anything like that in an art museum. But in peoples homes, sure. This is the kind of art street-artists sell to tourists.
It is easy to see why they recommended him architecture instead though. The buildings are drawn technically good and precise, but they are also the only thing that really works. Nature and people looks pretty bad. But of course with appropriate training he might have learned that also, who knows.
I have zero artistic talent and the only art I know is what I learned from an art appreciation class in highschool and and art history class in college. With that being said, those paintings look pretty similar to the kind of stuff I see in museums or in people's homes. I was expecting to see crude stick figures based off of the descriptions.