Many people are shocked when the price of something (anything) raises quickly over a short period. The only explanation they can find is that is it a bubble and the market is behaving irrationally.
That is a very lazy explanation, and we, as a human species,
See, when the intrinsic value of something is easy to grasp (say a barrel of oil, or a tulip), then there may be a simple relation between price (what you need to pay to get something), and value. Is your wife's smile worth the $10 that you are paying for a bunch of tulips? Maybe. If the same bunch skyrockets to $200 in a week? Maybe not. Then you can say that tulips are in a bubble.
But cryptocurrencies are different. They are new, and their value is still being understood. Granted, some coins look, smell and walk like rubbish, and they are probably worth zero, zilch, nada. But other cryptos look stronger.
The truth is that the crypto trend is real, and SOME coins will make it big in the future. Which ones? It's hard to tell. There is still a lot of innovation out there, and new coins (and forks) are coming with new, advanced, and valuable features. Some are better for financial transactions, others for faster and low-cost international sends, and so on. The fact that major banks, organizations, and governments are working on crypto-projects tells us that the trend is real, and it should not be ignored.
When will we know the real value of cryptos? Probably never, just we don't really know the real VALUE of fiat currencies. After the U.S. dropped the gold standard, the American Dollar went from being backed-up by hard cold gold, to being backed up by the promise of the U.S. government to defend (yes, militarily-speaking) its currency. (I could derail this post on go into conspiracy-theory mode, but I won't do it.)
Only when we see a better picture of the USE of some coins, we will have better data points and better forecast the value