I guess that's part of the natural evolution, I mean when people says that a certain invention is going to fall and it will be doom, guess what, it will go the other way around. Just like in the beginning, yes many people invested on bitcoin but sell early because they think it's going to die. And majority of them are not regretting their decision to sell early because bitcoin really took off in the last 10 years or so. Not to late to invest right now, the price is very cheap so take advantage of this situation.
That is the standard response people have to anything that is new and they do not understand, and while they had been right about some of those new inventions and those inventions did disappear, they have also been wrong about technologies that changed the world.
A few examples of this are cars, electricity, television, the Internet, computers, smartphones, video games and of course bitcoin, technologies which the average person did not understood and claimed they will disappear, only for those technologies to eventually form an integral part of our modern world, as such as long as we see potential in a technology we have to follow our own instincts and avoid doing what the majority of the people do.