I said that given a move away from .NET, Node would have been a better choice. I think Node is more open source friendly for a lot of reasons. For one thing, if cross platform friendliness is a primary driver, the Rails stack doesn't run easily on some of the most popular operating systems. The dev setup instructions are getting better, but they all began with "step 1. buy a mac". Is that really more enabling to the 2nd and 3rd world developers Jeff mentions? It's admittedly gotten better as they've added some Linux docs.
I also listed some reasons that C# is not really a non-starter for open source. Jeff's first two points don't really sell Ruby over .NET + Mono to me, and I explained that I don't think Jeff or StackOverflow really participated fully in the .NET open source ecosystem in a way that gave them a lot of value. There are a lot of self fulfilling prophecies in the .NET open source world.