It's all about the money. People care about professions because "female" professions tend to be paid less than "male" ones.
"The ACS also reported that men are more likely to gravitate toward high-paying nursing jobs. The highest representation of men is in nurse anesthesia, a role that often pays six figures. According to the ACS, about 41 percent of nurse anesthetists are men, and their median earnings in 2011 were $162,900. Among nurse practitioners, 9 percent were men making $96,400 per year on average."