What he probably meant was if Bitcoin catches on in any meaningful way the price must rise. If it never catches on it's likely the price will go close to 0 due to lack of mining security.

The dollar isn't necessarily Bitcoin's competitor. So maybe the dollar is good because it has such a power behind it. But what about all the other currencies of the world? Can you say they are all better than Bitcoin also? Try thinking about it in a less US-centric way.