It makes sense new collectors begin with Base, Jungle, Fossil, as its the literal beginning of the tcg. After I returned to Pokemon and bought southern Island, getting Base, Jungle, Fossil was a top priority. I went through all the set goals and then graduated to japanese promos and trophies. I think that is the natural progression.
There are a lot of sub sections in collecting. Even within vintage, some people only do Base, Jungle, Fossil, some only do up to neo destiny, some only do wotc. I think their entry point is par for the course. These guys are brand new, so only time will tell how deep they chose to go.