I don't believe Prelude was speaking against the idea of learning a new operating system. She was just taking some offense to the OP's direct (almost demanding) opinion that everyone in the forum should "Start using Linux."... and essentially the only reason he gave was "just because..." If you read my original post, you might see that I agree that people who wish to study a cross-platform language (such as the one this forum is based on), should be learning to write it in multiple platforms. However, it does not excuse the OPs inability to produce some decent reasoning to switch to Linux as you had done just a few posts later.
Anyway... I won't speak for her, this is just what I took from her post.