Because those fish mentioned are indestructible. Don't need to know how to keep fish propperly also can survive. Don't need to spend any money on equipment to keep these fish at all. Precisely why the Flowerhorn fad took off in Malaysia... because u don't need to know much and the fish still stays alive.

The average fish keeper in Malaysia will spend a couple hundred dollars buying a fish they think is 'nice' or auspicious, but then would be hard-pressed to buy propper equipment to keep the fish or decent food to feed it.

That's just the way it is.