No. That's got nothing to do with anything though. My wife has a degree in maths and works as a project manager at a big consultancy, I have a degree in comp sci and write Java all day. How many people really work in areas closely aligned with what they studied? I've used to no discrete math or graphs where I work...
I'm just showing you how it's possible to do a PhD then get a good paying job at the end. This removed the worry of missing out on 5 years of salary.
Maybe that's one reason. I think there are other reasons too.
Why do people want degree graduates? Because it shows they can finish things, because it shows they are smart? because it shows they have drive? Many reason are given for hiring grads.
Somebody with a PhD in comp sci would have pretty much proven they are good with very difficult problems and have the drive to see things through to completion.
What qualities do you think it takes to finish a PhD? Some employers seek out those qualities and a PhD is a good indication that you have those qualities.
I'm just showing you how it's possible to do a PhD then get a good paying job at the end. This removed the worry of missing out on 5 years of salary.