Earlier quoted context omitted.
True but it does show exploration and curiosity to at least try another language or two. If you’ve been doing .NET or PHP for 5+ years without even trying something else I’d treat it as a red flag too. Level of interest is the #1 quality in the great programmers I’ve been around. If you aren’t exploring even a little that’s a concern.
Making the assumption we're talking about good programmers here: If you've been doing .NET or PHP for 5+ years, you're just now starting to become an expert at those languages and their environments. That 5+ years experience could just as easily display dedication and care about their craft; a commitment to understanding the ins and outs of their tools. For example, who would you rather have write your payment gatewa…
I'm a contractor - I use whatever language the client is going to pay me to use. In the past that's been C, Ruby, Tcl, Perl, Python, a tiny snippet of Java, etc.