NO, it is not. Mac OS is not either. Free as in beer means free as in beer - no cost. You cannot LEGALLY get Windows for free. Which leads to the OTHER free, which is free as in freedom - which clearly the other two are not either.
Buy a new computer that someone else built, like most people do, and Windows or OS X comes with, no extra purchase necessary. For most people, it's free. It's not even a hidden cost, as it's often compensated for via bulk agreements and pre-loaded software. Deleting the software does not delete the OS, so it's effectively free. Most people never buy a standalone copy of Windows or OS X.
Most people just want to use their computers to run the software they need to run. Your idea of "free as in freedom" is pointless to them, because it affects them not at all.
What kills Linux for most people (including me), is the fact that, to do anything even slightly different than what ten thousand other Linux users have already done is an absolute nightmare.
Want to install a piece of software that isn't' in your OS's repository? Hope you know your way around Make and the GNU compiler! You need to be a wannabe programmer just to install software? Really?
Got a piece of hardware with no built-in driver? Hope you don't wreck your machine when you re-compile the kernel! Again, seriously?
Hope you know your thousands of config files inside and out, so you can re-configure your system when a piece of software mucks a bunch of them up!
In my experience, Linux is best when nothing ever changes on the system. No new software, no editing settings, once it's set it's set and nothing changes. That makes it perfect for many kinds of servers, and embedded systems where the user is sandboxed away from the core system. In fact, I prefer Android as a phone OS, and in that case I think it is an excellent experience.
I'm glad Linux exists, but I used it as my personal desktop for two years and honestly, if you tried to pay me to use it I'd probably look for another job.
I want to use my software, not fight my OS. As much as people bash Windows in nerd forums like slashdot, in the long run it gets out of the way a hell of a lot better than Linux does.