Empirically true. See: PonziCoin https://techweez.com/2018/01/26/ponzicoin-crypto-scheme/

DogeCoin was supposed to be a parody and people actually bought it.

Also my phone does not flag DogeCoin as a misspelled word.

Anyone who invests in this stuff is either really dumb, or morally impaired yet smart enough to exploit people who are really dumb.

You mean Elon?

Did Elon seriously invest in Doge? I was assuming he was just having fun, in his own way.

Pump & dumping any investment is often very fun, at whose expense is a matter for the courts.

Do people really not automatically assume that he made money each time he mentioned it?

As someone who has made a bit of money in crypto, there's no reason I can't be really dumb and morally impaired, but lucky. I will note that moral impairment and intelligence are not highly correlated as far as I know.