Yes, but the fact that most websites these days have to load seven dozen javascripts and CSS stylesheets to become usable probably doesn't help either
The reasoning behind this is a wish to avoid annoying or "unestethical" flicker from one font to another once the font has loaded.
That's great if you're on 10mbps or more.
Now put yourself on a 64kbps barely functioning link on the metro, you have DLed the 800bytes of article text you really want read 5 minutes ago but you're still waiting for that one special font which webkit requires to be able to see anything. And that wont fully load until you're off the metro.
I tell you: Lesser things can drive a otherwise reasonable person completely mad.
Don't use custom fonts on any mobile stylesheet ever. Thanks.