Of course not, but it does affect your credibility, and rightly so.
I don't know what his track record is on technology in general, but dismissing something as important and revolutionary as the Internet makes me seriously wonder about his ability to understand the impact of new technologies.
It doesn't for me. A lot of people were wrong about the Internet. It was a revolutionary technology, but for every revolutionary technology that has succeeded, there are plenty that fail.
If we look back 10 years from now, BitCoin could either be hugely successful or a mere afterthought. I'm not going to hold anyone accountable for being "right" or "wrong" about predicting its future. But I suppose this is why sensationalist journalism works.
Being wrong on technology as an economist isn't an indicator in this case. Bitcoin is intended as a currency, his skepticism is directed towards that. His background as an economist and success/failure there should give weight to his views.
I don't know what his track record is on technology in general, but dismissing something as important and revolutionary as the Internet makes me seriously wonder about his ability to understand the impact of new technologies.