And a commentary:
Most of those humble and modest people is just having problem with expressing themselves. By remaining silent and peaceful (and not expressing negative emotions) they cause sympathies from the other people, which only makes the thing worse. They take it as reward and stimulation to remain silent and don't try to change people's minds. Their behavioral curve looks perfectly immovable from the apparent course.

But poke them with just a bit more self-esteem (for example power over whole $10M). Set them free. And they will show off where this curve really goes. The real problem is that after they dare leaving the behavioral area by which everybody knows them and finally start to explore their real selves, they will make the first baby steps playing with no-small stuff, unlike the other people did. Thus the consequences of mistakes will be also huger. Even worse: in those baby steps they will act very likely just like children while others will expect grown up reactions from them. This would very likely lead to an isolation from all those people who don't understand them, and treating yesterday's acquaintances worse than total strangers.

This end-result isolation didn't appear from nowhere. It is the same isolation layer they used to hide their undeveloped personalities from the outside world. Now they have to isolate (likely) all those people whom they were 'hiding' from, and live the 'new reality'.

Those people didn't go corrupted. They just didn't develop freely / didn't have chance to steam off their first steps at the young age or they just simply got chance to show off how corrupted their inner (us previously unknown) world was.

Sometimes I think I should've studied psychology / psychiatry.

"Only the dead have seen the end of war"

Plato

"It's an extreamly shity situation, buts its the fertilizer for our future.."

Lennart Meri, former President of Estonia. RIP