The biggest benefit for me when it comes to having a private room to study is that I can do light physical activity while I'm taking a break, which most often invigorates me. This is much more convenient, and a supplement to, "properly" working out by donning clothes to sweat in, perhaps going to the gym and the like. I can't really take these breaks when I'm around other people because I'm too shy, and doing pushups while in such a context makes me feel that people think I'm trying to show off (and no one would be impressed anyway).
Sure, less noise and less visual distractions of other people walking by is great, but I most often listen to music anyway. The article claims that this is suboptimal, but it is what I prefer, and I sometimes listen to music without vocals if the music is too distracting.
Thankfully there are a fair amount of places I can study at my university, most places with other people and sometimes places where I can be alone (if I feel like being alone).
On a slightly other note: I wonder how much of the hatred of cubicles (which I have the impression of not being thought of as truly 'open' office) is disliked because of the noise and such around them, and how much it has to do with perceived status and feeling like a 'corporate drone' without the privilege of having one's own door?