There are many things that I would do for free that I wouldn't do for many thousands of dollars. Once you accept money for something you create an expectation that the thing will get done.
Imagine the level of privilege required to refuse to deal with a slip of paper for $999/hr. Checks are a pain in the ass roughly equivalent to having to clip your fingernails every once in a while.
First of all, it was a joke. Second, if a job is offering me $999/hr and asks me to use cheques, something's really fucking wrong and it's a scam.
Third, "blah blah take a picture with your phone" -- y'all talk about privilege as if you ever lived outside of the US. Where I'm at, dealing with a cheque involves finding a bank that will accept them (Mine sure as hell doesn't), and opening an account there, then most likely depositing it in one of their rare remaining branches because there's no such thing as photo-deposits or w/e.
Foreign checks are admittedly a bit of a pain; I need to go to a bank branch (though not exactly a $999/hr pain). But I routinely deal with domestic checks and it's <5 minutes with my phone's bank app.
How hard could it be for you to simply take a picture with your phone? I can understand opposition to writing checks since you'd need to go track down your checkbook or even get one if you don't already have one. But cashing a check is completely trivial.