That's not even remotely true. GPL does not prevent any commercial use, when others (like BSL or the O'Sassy license here) explicitly prevent commercial use...
Are you kidding me? If you link against a GPL library in a proprietary commercial app, the GPL's copyleft infects that code and you'd have to release it under GPL.
Explain to me how that doesn't prevent commercial use? Are you going to say "well technically it doesn't prevent it"? No one cares. Commercial projects avoid GPL like the plague.
