Thanks Alonzo for your level-headed post.
I'd also like to add that other bubbles (like the real estate bubble) were caused by the Federal Reserve keeping interest rates too low for too long, causing malinvestment. In fact these boom/bust business cycles that bring us recessions and depressions can be avoided by taking the central banks out of the picture.
With Bitcoin, there is no danger of this kind of manipulation.
This is a fascinating insight that I haven't seen mentioned elsewhere. Our collective concept of what a "bubble" looks like is directly coupled with central bank manipulation, so to use the term in the same sense shouldn't actually apply to bitcoin.
That's not to say bitcoin isn't possibly overvalued at the moment.