I used to work on LAMP before moving to the microsoft platform. Sergey Solyanik did the same and his post on the subject is just... hum.. pragmatic! Here are my favorite parts of the post:
(...) "First, I love multiple aspects of the software development process. I like engineering, but I love the business aspects no less. I can't write code for the sake of the technology alone - I need to know that the code is useful for others, and the only way to measure the usefulness is by the amount of money that the people are willing to part with to have access to my work.
Sorry open source fanatics, your world is not for me! "(...)