As a nurse I may have a view slightly different than others here, so here goes:
Nurses for the most part are in the role of carrying out orders. The doctor formulates the diagnosis and develops the treatment plan, and the nurse carries out the majority of the dr's plan. The nurse is responsible for letting the doc know of any deterioration/improvement in pt status. In my department (an ER) we're pretty lucky in that we have a very collaborative relationship with most of our docs (there's always some exceptions) and they usually take our input/opinions into consideration.
So why not nursing? For me, while I don't mind carrying out orders, I'd rather be the one doing the diagnosing and prescribing. I want to have the knowledge base that allows you to see something and develop a plan of care that treats it. For example, we had a kid come in one night with a hx of vomiting/diarrhea x3-4 days. Most of us nurses just figured it was a virus. Then we saw her labwork, which was so screwed up we didn't know what to think. The doc takes one look at it and says, I think she has HUS (hemolytic uremic syndrome). None of us had ever heard of it (and some nurses had 10+ yrs exp), and he (2 yrs out of residency) takes one look at the labs and knows what it is. That's why not nursing. Nursing is great for some, and I admire those that have been doing it for a long time and continue to love it. I like my job, but after 3 years, I know it's not for me. I want to have a much broader knowledge base and scope of practice. I don't think one profession is better than the other; they're very different and equally deserving of respect.
Speaking of pay, I'm 3 years out of nursing school (with a BSN), and my take home pay after taxes is around $30,000-$32,000. And I'm in a larger city. And that's WITH my critical care/night shift/weekend differentials. I don't expect to make a doctor's salary (or even close to it), but come on! Doing work that saves peoples lives deserves a little more than that.
Anyway, that's just my $0.02. It's a personal choice and one that should be very well researched before one is chosen.