Knowing a few other mechanical engineers myself, finding a decent paying job as a mechanical engineer was nearly impossible. At least 10 - 15 years ago.

So the revelation from his story is that working as a bartender can bring in quite a bit of money due to high margin of alcohol and bigger tip.

I don't know anything about the profitability of the area of engineering that he is interested in. Perhaps you could look into it and report back.

I'm sure he was a very good bartender.