That being said, by being a skeptic, I think I'm right more than I'm wrong. For every "internet" that I've called wrong, there's a "3D TV" or "Segway" that's I've correctly predicted would fail to live up to the hype.
These revolutionary technologies that shift our daily life come along far less often than people like to predict. Even if the technology is superior to what most people are using there are still a ton of factors standing in the way of mass adoption (see VHS vs Betamax). You know that Tolstoy quote "All happy families are alike, but every unhappy family is unhappy in its own way", I kind of feel that way about new technologies. There are a million reasons technologies can fail to catch on, but they have to walk a very narrow path to succeed.
So, as one of those type of people you're asking about, I guess my reaction would be "oh well". I'm right more than I'm wrong and the downsides of a false negative and less than the downsides of a false positive. If thought the internet was a load of crap and I hop on the band wagon a few years late, oh well, it's not like I've missed out on it for ever. On the other hand, if I bought a 3D TV when they first came out, I'd now be stuck with an overpriced TV with a feature that has almost no support.