[mattferderer]

I think you might want to take a slightly different look at it as I have found the opposite.

You also might need to find better C# programmers as I honestly don't know any C# programmers who only know one language or one editor. An awesome IDE is big perk to development. I don't think that should be considered a con.

.NET also has tons of "magic features" like Data Annotations & Attribute Tags for those who want some magic that reduces code & helps get stuff done faster.

JS & other languages reference it when looking to introduce new features.

C# is anything but dated. One could call it bloated as it is one of the most flexible languages with about 10 ways to do anything. That is a strength & a weakness of any language that positions itself as a Swiss army knife type tool that wants to be able to be used everywhere. With C# you can write a lot of nice fairly functional programming style code & OOP code which is a nice perk.