It's a little more complicated than that. First, the job was more painful than expected. Second, they lied to him about starting salaries, telling him that all new employees in that position started at the rate he got. Then they hired another employee into that position for higher, just weeks later.

And finally, you have to ask for things to get them. If he just quit without asking, he'd never know if he could have gotten that raise instead. Now, he knows. At a different company, he might actually have gotten it.

I think he made exactly the right decision at each step, given the knowledge he had at that point.

Personally, I probably would have chosen to stick it out at that company until I found that second job, instead of quitting on the spot, but that's me. But the end result wouldn't be that different.