You don't even need to have a serial number.I expect it to run out of the box, no special downloads, no foreknowledge whatsoever, just as if I were installing any version of Windows
User friendliness is a good thing, but Linux is NOT claiming to be "easier" than Windows. It's for people who know what they are doing, and need finer control.
Ubuntu is trying to cover the middle-ground, and I think it's doing a fine job. With more "easiness" there goes less control. It's a trade-off. How much control do you get with the Windows installer? I guess you get to enter the serial number...
For a (almost) computer-illiterate person, Windows is easier to use than Linux. No one is trying to deny that.
Development environment is a matter of personal preference. GCC, for example, lists Linux as a primary target, and Windows (MinGW) as a secondary target (bugs not fixed as quickly, etc). As a result, it's more robust on Linux, and have things like multilib (32-bit/64-bit with a compiler switch). The GCC build system (for compiling the compiler) also heavily rely on POSIX features, and follows UNIX conventions (configure and make).