"talk to more C# devs from different kinds of businesses"

As a PHP dev who's done C#, Java, Perl, CF, VB and more... I'd rarely find any other PHP devs at our local MS and Java user groups. In a few cases, I was the first "PHP developer" some of these people had ever met.

Java/C# tend to be used in larger enterprises, and they tend to be used by people who are... somewhat more 'corporate' in their life. Go to work, do the job, go home - going to local groups/conferences and socializing with non-work tech folks is often not high on their priority list (family, etc may rank higher).

Maybe it's generalizing some, but it's also a lot of my experience over the past 20+ years. I've met some phenom tech/dev folks at pretty much every event I go to, and I meet more "professional" polyglots today than I did 15 years ago, but I found I had to make an effort to find them (beyond just going to my own favorite events).