In most enterprise environments, you have your choice between .NET and PHP. Given the option, I'll take PHP, thanks.
So, no, you're not necessarily stuck between these two options (or Java, which is another popular choice in the enterprise scene). Scala was chosen specifically, among other things, because Twitter had a lot of Ruby developers who would cringe at the idea of PHP, Java, or .NET.
Besides a nice modern languages vs PHP. I know what I would choose.
PHP as a choice for an enterprise? Jesus. Could somebody show me a 2-3 year old PHP project which doesnt have code rot? To even speak of 5 year old code that is still readable and somewhat maintainable.
Java is where its at for the enterprise.