On the one hand, you are right in not seeing much PHP in enterprise. However, your assessment of not seeing LAMP much in enterprise is bogus. The difference being most enterprise LAMP models are Perl or Python for the P, not PHP. And still others use Ruby. And many, many are hybrid models. Google, for instance, uses a lot of Python on their servers, but for many of their web pages they use PHP. Google is not an Enterprise? Yahoo uses PHP extensively, is not an Enterprise? Gag where you want, but get your info straight.
Now, I like C#, and so do many developers I know. But I, and many of those developers, strongly dislike ASP.Net. Where I work (yes, in the "industry") we do both app and web development. We use both LAMP and .Net extensively, depending on the case scenario. And I know many, many developers whose employers use the similar deployments. And we have "real jobs".