Damn, he'd make more money working for McDonalds.

At McDonald's, there's a very obvious causal relationship between paying some money and getting a hamburger, so of course people pay. With nginx, you just apt-get install your hamburger, and you're done. Donating would hardly ever come to your mind in that process.

I assumed so, its a sad state of affairs.

Its mostly private persons, where are the companies making huge profits from nginx?

So its good they do like this with nginx plus, even if the open source version suffers, I wish the developers make tons of money.

Convincing your boss you need to pay $1500 for a software license for some core software is fairly easy and all companies have procedures to handle it. Convincing your boss that you should donate $1500 to some open source hacker in Russia who wrote the web server you use is much much harder and there may not even be procedures in place.

A publicly-held corporation could (in theory) be sued by its shareholders if it just gave away profits like that.