Can you replace Ubuntu? Maybe, if you are OK with 14.04 LTS level support. Certain simple things straight up don't work -- you can't send a ping without an admin level windows shell (sudo wont do it either). You also won't magically get driver support for hardware that works in Linux, but not Windows (if you think this isn't a thing, try plugging in a random USB-to-something adapter without finding obscure, broken, or nonexistant drivers on Windows). If you just need access to some tools that only run on Linux, I've found WSL invaluable, so long as those tools are available on Ubuntu 14.04.
Can you replace Linux in general? Nope - I'm a 90+% Linux user for work and home, and neither Debian, Ubuntu, or its derivatives work for me, with the notable exception of some server and embedded applications. If you want a wide variety of up-to-date software, there is no replacement for something like Arch.