Hi, I'm nearly finished with my studies, and have had some of the same misgivings as you are having, mostly from hearing some nurses complain bitterly about their jobs.
Work satisfaction seems to be low on the list, doesn't it?
Tell you what, your post made me realize something I think is important: All this study, all this intensity, all this attention to detail to support the patient, our colleagues and our employer--and not too much said about taking care of ourselves!
I think a lot of the complaining is plain old garden variety burnout. It happens in every profession--but in ours, the protections are actually written into the Code. (Just learned that yesterday, as a matter of fact.) We are often just too tired to take care of ourselves, though, and it seems that natural caretakers often put themselves last.
Also recall that humans are built such that we may not say anything until something is wrong, so the happy nurses might just be the quieter ones, much of the time.
I think there are plenty of nurses who are happy with their profession--I plan on being one myself.
Thanks for the post--hope some happy nurses get in here and chip in their two cents too! (BTW, kudos for getting in on the master's entry level. I didn't know about that, already have a master's in a related field, but took the ADN route--no regrets, just would have liked to have known.)