The US has more millionaires than not only any other country in the world, but more than the next dozen or so combined. The US and Asia are pretty close in terms of billionaires, but that is a very small group of people (just over 1000), while the number of millionaires is… in the millions.
Yet if you play any mobile game online, the odds are pretty good that when you run across a whale, they will be Asian (basing this on player name, but I doubt many US-based players are using Asian names). Why is that? Again, the number of people with enough money to whale-out in a game and have it not really matter (spending 10k matters as much to someone with millions as spending $5 does to someone earning 40k) is higher in the US, so why isn’t that reflected online?
Maybe it’s a new money vs old money thing, where people with new money are more likely to spend it foolishly. Or maybe it’s just a culture thing, where people from Asia are more likely to whale-out compared to someone in the US/EU. I honestly don’t know, but maybe someone with more experience with that region (Az?) might be able to chime in.
Somewhat related to the above, right now PUBG is still experiencing a wave of hackers (mostly in solo TPP, which honestly a lot of people don’t care about, but still), at least as it relates to the pointless leaderboard, and those accounts also come from Asia. There has been a push on Reddit for PUBG to be region-locked, and while that wouldn’t completely fix the problem (it’s not that difficult to get around a region lock), it would keep the most amateur of hackers out, which is what a lot of these accounts are as they are simply buying and using a popular hacking program.
The more work you require someone to do before they can successfully hack and disrupt your game, the lower the overall number of people who will do it, and in turn the lower the impact the hackers have. If I see one hacker in 100 games, I honestly don’t care. If I see one in every 5 games, that’s a problem. Right now my own experience is far closer to the one in 100, but again I don’t play PUBG alone in TPP, so maybe just for that one game mode the issue is as bad as Reddit makes it out to be (not likely).
Hardcore Casual 
I can’t particularly speak for all of Asian culture or anything, but what I can say is that most fans of something over there are very fanatical of that something. Which makes sense given the cultural and economic forces often at play. For example, the PC gaming market in Japan is almost nonexistant (although it has much improved since Dark Souls was released). Just imagine your gaming life without Steam sales, without Humble Bundles – it would mostly be relegated to consoles and hand-held games. Then imagine that renting games is literally illegal (as it is in Japan), and buying secondhand games requires special trips to Akihabara or similar destinations. Add into that decades of a stagnant economy and relatively high game prices, and you get a scenario in which you can either play 5-6 games, or whale out in 1-2 of them.
As for other Asian countries, all I know is what probably amounts to stereotypes. Basically, it’s much more accepted/expected to spend money on status symbols, which can be flaunted in-game pretty well if there are P2W elements. Then again, just imagine if your gaming budget was able to be funneled into just one game. I’m pretty frugal for the most part, but $50/month on games isn’t unusual. Dropping $600 into some random phone game over the course of a year could get you pretty far, especially if money directly turned into power.
Whales I’m talking here are those that spend in the thousands, like anyone who has multiple lvl 5 legends in CR or an instantly maxed CoC builder base. I think it would be much harder to spot someone spending about $50 a month on something, unless its a single visible item worth $50+ or something like that.
Probably some part of it is due to culture. The games Asians have been exposed to are all grindy microtransaction gamblingesque for a very long time. There’s a general culture of being intensely competitive, and being afraid to lose out or look worse than the Joneses, add on general male ego and hierarchy squabbles and you have a group of whales who are okay with dropping heaps of money on a status symbol for prestige, be it a car, a house or a really shiny weapon that gives them awesome power.
Gambling in the hopes of making a profit also seems to be more acceptable culturally? Though I could make the similar stereotypes about the West and card games and Las Vegas, so I dunno.
whales are cool