I'm in a real mood today, let 'er rip...
However if you extrapolate this logic, nothing free would have any value, like the Apache webserver, or Google Analytics, or heck, Google itself!
Apache is a bunch of cryptic crap that even hard core apache users still don't fully understand half the time. If you had a quality web server you paid for you would expect easy to install rules, tools to set up all those crazy cryptic config files, etc..
It works. It's free.
However, if I sold it to a customer I'd expect a refund after they tried to configure it.
Google keeps taking things away from webmasters, penalizing them for god knows what, trying to dictate everything they do and making them all insane.
It's free. It works.
However, if I sold a website to a customer that ranked and it vanished the next week, which happens all the time, I'd expect they'd ask for a refund which is why I got out of that game.
While we're at it, Facebook is also free, everyone uses it but screams #*$! murder as Facebook becomes less user friendly by the day and took what we loved and turned it into something else, but it's free, deal with it.
Twitter is the same way, initially you could build add-on Twitter apps to make it actually usable and then they cut the API and suddenly we're all trapped in that horrible hell of malfunctioning javascript twitter webpage and an equally atrocious twitter app, but it's free and all you can eat, enjoy.
The whole world uses PHP which is 100% slow buggy hackable crap, Perl or Python would be better choices, yet we gobble up the garbage when ALL THREE ARE FREE!
You get what you pay for, it's all free, it's all a maddening pain in the ass, yet we just keep feeding that beast instead of fixing it because people are mindless sheep that go with the herd...
... even when the herd is running off a cliff to certain doom, such as drinking the Google kool-aid.
If there were better alternatives to all of the above, even paid alternatives, I would gladly use them but the cheap masses would not.
Basically, all of the ads aimed at the people with money support the sites for those that couldn't afford to use a fee service. If all of the unhappy cash-packing consumers found a paid platform and moved off all the free crap where they have no say whatsoever, the free stuff would vanish under the migration and create a digital divide.
It will eventually happen, in some areas it already is happening.