Simply put - if you are a good developer and the language isn't completely out of whack for what you are attempting to do -- for instance, web apps and fortran probably aren't optimal -- the language shouldn't matter in terms of getting things done.

I know of a couple of startups doing well that are built using PHP. One doesn't even advertise the fact that they use PHP because they want strong developers regardless of language. Fact is, PHP is pretty darn simple to pick up, not much harder to do things correctly, and has a lot of third party/opensource support. Is it cool? No, but when it comes to language wars, this pretty much sums up my feelings:

http://programming-motherfucker.com/

Personally, there was a startup about 6 years ago where I wanted to use Python. The IT guy and I got into a discussion about PHP vs. Python. He was more comfortable in securing PHP apps. I was enamored with Python, since I was writing a bunch of stuff with it. After exploring mod-python vs. mod-php, mod-python had bugs and wasn't nearly as mature, so we went with PHP. The language didn't matter, it was about getting things done.

There are lots of "cool" languages out there, a good dev will run circles around a mediocre dev who focuses on things that are "cool".