Buggrock, technology always has a parabolic adoption curve. Did you stop using facebook when it became popular?
Bitcoin's usefulness actually increases as more people get into it and put more money into it. As it stands, the cryptocurrency market is TOO SMALL to be taken seriously by large investors or large retailers (unless it is as a gimmick). If the assumption is Bitcoin succeeds (and that's a big if) it will be way higher than it is today.

Sure, there may be a temporary crash to $500, but why would you take the risk and wait? It could just as easily go to $1100... then 1300... then 1800. And you will be sitting there waiting for it to crash by 50%.

If you are serious about investing in cryptocurrencies and are nervous, invest over time at set intervals.
Stop trying to read the market, it's something no one has ever seen before. Anything goes.