From where did you get the data that Koreans are investing more in altcoins rather than Bitcoin? Did any exchange published it? Have you read an article somewhere? I would like to have a look.
I am not sure about Korean weather they like gambling or not. If as a community Koreans like gambling, they would invest in altcoins. Otherwise I don't see any other sane reason here for not investing in Bitcoin.
Maybe that's just his assumption, while he doesn't know the actual data why say so most South Koreans are more altcoins than bitcoins, so I'm not entirely sure what the OP said.
Actually it is up to each individual whether they want to invest in altcoins which we consider as gambling or bitcoin, everyone has a different view including looking at the crypto market, maybe some think this is gambling so they invest in altcoins and expect quick profits in a short time, because altcoins are pump and dump.