This is especially visible when trying out various new programming languages. I have written exactly one .NET application in my life and I absolutely loved it that I could just downl... I mean buy the Visual Studio, install it and start coding, debugging and deploying the application. The same story with Delphi.
A very different story is about Python, Haskell and all things Java related. You need to download compilator, then you need to find and download IDE separately, then you need to figure out how to make it work with the debugger, if you're lucky enough to get it working at all. It takes time and effort that doesn't benefit me. It's all reading instructions, changing paths in configuration files and setting environment variables.
And the reason why this is done so is because as I mentioned some people absolutely love the idea that they can use any tools in any configuration that somehow after some effort work together. And people who like to tinker are the people who write open source. So there.
Also making good product = fun, making good setup = boring.