Well, I listed several reason that one might be against bitcoin that don't apply to gold. I'll add one more. Given Bitcoins stability record, given that it is at all time highs right now, it is a terrible time to invest in Bitcoin (though that could change tomorrow).

Having said all that, I don't think Peter Schiff is right in this case. I think Bitcoin has a long future ahead of it. But one does have to wonder if his Facebook/Myspace comparison is accurate. What is the advantage of Bitcoin if another cryptocurrency comes along that does everything better? Arguably that's happened already. So what is to keep everyone from moving their investment from Bitcoin to a technologically superior cryptocurrency and thereby making Bitcoin worthless?