Why I'm jumping off this ivory tower

At several points in my university career I have seriously considered going all the way for my PhD and becoming a professor. I am really interested in science, in conservation of the environment, how the world works, and strongly believe that science can play a major part in improving the quality of life for disadvantaged groups around the world, be they in a third world country or our own backyard. I know I wouldn't be the world's best teacher, but guiding graduate students is somewhat appealing to me. Besides, those three extra letter behind my name would be pretty cool.
But I'm not getting a PhD. As much as I'm enjoying my Masters, I am feeling the lure of government work, where I can be paid extremely well, have great job and pension security, flexibility for when I have a family, and also do my part to make Canada better. Another reason that I'm not getting my PhD is that I am terrified of the comprehensive exams process. I think I would cry for about the month leading up to it. But one of the most significant reasons I don't want to become a Professor is because of my sex, and the real discrimination which is still placed against it in academic settings, especially for science.
I am currently working in a department strongly deviated from the norm, with several female professors, one of whom was head of the department for the last year. The graduate students are predominantly women as well. And while we are part of an extremely large university, recently ranked 12th best in the world, I think that we have managed this because its a very small department, in a small part of the field and with several unique research interests.
My undergraduate career culminated with a fourth year thesis in a much larger department, and while again the undergraduates were mainly women and there were no overt indications that biology is difficult to get ahead in, I observed several things. There were 2 female professors with tenure out of nearly 30 professors in total. One the 2 women happened to be my supervisor and she had managed to balance both a research career and a family, but often made comments that inferred that there were a number of members of the department who didn't take her seriously, due to the focus of her research, her vehemence that scientists must speak for the environment and not try and remain neutral as some would suggest, and that she did not commit insane hours in the office so that she could go home with her children. She worked several hours at home every night (I have e-mails sent at 11:30 to prove it!) and involved herself in numerous department committees and processes, and was an excellent lecturer. But there was always the sense that she wasn't quite as serious, not as much a real scientist.
I recently found a blog linked to by one of my dear friends who is being very brave and pursuing her PhD, called FemaleScienceProfessor, which is written by a leading female researcher in the sciecnes. I must admit to reading several of the posts this afternoon. The anonymous blogger relates people asking about her private life in interviews (which is pretty much illegal), being constantly assumed to be a student or post-doc rather than an actual professor, and other moments that her credibility as a researcher is questioned due to her sex. It's a depressing read in some cases but I am also very impressed with the author for expressing her problems so well and serving as an example for those braver than I. I'm jumping off the tower, but wish all my female brethren the very best of luck.