I would think that someone who would go so far as to get a masters degree in a topic would also be curious enough to know exactly how some of the tools used in that field plug together and work? Am I wrong here?

Maybe you're right, maybe you're wrong. But the power supply and the case are probably the two least interesting parts of the computer to somebody with a Master's degree in CS; it may well be the case that she knows a lot about the cache in her cpu and the various sockets in her motherboard, and she just doesn't care about the PSU because as long as it supplies enough power, it's boring.

Also, let's be clear here. At heart, building your own computer is like playing with Lego, except that each piece is very expensive and you're terrified of breaking it. Plus there's probably a specific order you need to follow to make sure everything fits properly, but you get no instructions about what that order is, because it depends entirely on what pieces you bought. Also, if you don't already know what you're doing, it's entirely possible to buy pieces that just plain don't fit together and you won't realize it until you're elbow deep in the case searching for a socket that just plain doesn't exist.

As somebody who has gotten a master's degree in computer science and also built his own computer, I definitely feel like the master's degree was far more interesting of an endeavor and if somebody said "I'm really interested in computers, but not in putting them together; it seems like just putting tab A into slot A but all of the tabs and slots are poorly labeled", I'd nod my head and say "Yeah, that's basically it. I enjoyed building my own, but it's not for everybody".