It is not being a "corporate programmer" that sucks, it's working for someone that does not allow your creativity. I worked for a small division of Merck for 10 years and it was about the best job I have ever had. Our "corporate" was far enough away that the boss got to set the complete tone of the job. And he looked forward to seeing us shine and write excellent software. Two of the projects I was the IT project manager on made it into the Merck annual report. Not because the IT portion was so overwhelming, but I think because the whole project, including the IT portion, made a big, positive difference in the bottom line.
Then I went out on my own and worked as a contractor at a true "corporate" job. ANY ideas of creativity was immediately stepped on as being a waste of time. I made the mistake in 1993 of asking the boss if he wanted me to add a line or two of code to make sure the program I was writing would not break at Y2K.
I truly feel it is not where one works, but for who one works that makes a great deal of difference.