It still depends on what programmers you ask. Windows works fine for me, Linux did not work well when I tried it (but it was many years ago). Unix through XWindows from a pc was actually quite nice.
I think developers like users use feelings more than thoughts when choosing an environment. Yes, you can do some things on Linux that are harder on Windows but saying that missing "grep" is severly limiting you is strange since it is easy to install. And you have find in most editors. You can run Vim or Emacs if you want to on Windows. Powershell is very good but with a strange syntax. If that is someones problem they sound like they don't want to learn something new. Listing thousands of files in a folder is probably still faster on Linux but I rarely do that (I can't see the point in collecting many years of logs in one folder, for example). The main problem I have with Windows is that I have to restart the computer every now and then.
Yes, the way Windows locks shared DLLs and requires a restart of the whole OS instead of just the programs currently using the DLL when you install an update is, in a word, obnoxious.
Also, again I dislike the fact that Windows is inherently GUI-centric. Interacting with programs is designed to be done using primarily the mouse or a touch screen. Even Windows Server is designed to be used via remote desktop. Whereas for UNIX-compliant OSes the desktop and mouse are not required for anything, a skilled user can easily be more productive using only a keyboard, and anything a user can do can just as easily be placed in a script and automated.
Package management is also a major deficiency of Windows. Chocolatey is a nice workaround, but is a relatively young project. Windows did not have any package management for a long time.
Also for a lot of programming language packages with native code extensions, it can be difficult or even impossible to get them to compile on Windows. I can think of a handful of Ruby packages that flat-out do not compile, making Rails dev on Windows a non-starter.
