Comes from multiple attempts over a solid seven years and change to try and get a really usable, pleasant user experience out of any of the eleventy billion mutually-incompatible Linux distros.
My experience is that in recent years, installing Ubuntu is easier than getting Windows to run reliably at anything than snails pace, and things like getting it to recognize printers requires far less voodoo (what a change from a few years ago..).
More importantly, even if it isn't suitable as a desktop OS for you, the immense success of open source is demonstrated quite well in that most of us have at least one device running Linux (or less likely another open source Unix clone) in our house - even if you don't know it. Most routers and set-top boxes run a Linux version these days, for example. And of course any Android phone.
Both open source and proprietary software is hit and miss. The big difference is that if a proprietary product doesn't measure up, the company goes bankrupt and the product disappears, so you mostly get to see those which are at least modest successes, while for open source you get to see all the in-progress and failed projects too.