That is a great philosophical question, and different people will have different answers, all valid; however:
> "Installing Linux boxes to run Redis", I can't help but feel he's being a bit narrow-minded.
..
> Why not just tell Linux users to get a Windows box if they want to run that software?
This is not a symmetric win32<->linux case. If you're a win user, and you need Redis, you can run it today, for free, starting 10 minutes from now (30 if you've never done this before and need to download stuff):
download oracle virtualbox; download ubuntu server install, install inside virtualbox inside ubuntu, sudo apt-get install redis-server
And really, that's all there is to it; if you are an experienced windows developer with no Linux experience whatsoever, this will take you all of 30 minutes (25 of which just waiting for downloads). It actually performs quite well; not as well as running directly on iron, but probably not more than 10% slower than a native port that does everything right (The current native ports are 100000% slower during syncing to disk)
If you're a linux user and you want to run a windows-only server, that costs your $100 or so for a retail win7 license, a few hours of downloading and 20-30 minutes of active setup last time I did that. Want to fire that up on 3 developer machines? That would be $200 more, thank you. Reconfigured your virtual box more than 5 times? You have to talk to Microsoft before you can proceed.
So, really, what he offers IS a viable solution for windows developers. Really. Try it before you consider it "narrow minded". You might find the narrow mindedness was not where you expected.
> In fact, lots of software starts out as Windows software and is ported to Linux.
The few I am aware of are picasa and 7zip, of which I only ever use the latter. Do you have more examples?
It's actually significantly harder to port Windows programs to Linux than the other way around, because the Win32 API has about 100 times more functions, and the standard practice (cheerfully supported and encouraged by Microsoft) is to use all of them.