But how is the above sample 'unfree'?
The sample above is "non-trivial" according to the set of heuristics they are using, so they are just saying "if the program is not trivial, then you need to explicitly state that it is GPL for us to consider it free"
(as a consequence, my entire site won't work for users with this enabled)
I mean -- the websites you are visiting are bound to be using non-free proprietary software. At least a few of them.
Actually -- the routers your packets travel through are using proprietary non-free software!
The BIOS that boots your PC is non-free and proprietary!
Just throw your computer out -- that is the only sure way to stop using non-free software. (actually, don't throw it out -- just mail it to me ;)