A very very good explanation as to why BTC will crash even though blockchain is a good tehnology.
If you do not want to read the full link below, here is the key part of the comparison:
"
imagine that someone had found a cure for cancer and posted the step-by-step instructions on how to make it on-line, freely available for anyone to use.
Now imagine that the same person also created a product called Cancer-Pill using their own instructions, trade marked it, and started selling it to the highest bidders.
I think we can all agree a cure for cancer is immensely valuable to society (blockchain may or may not be, we still have to see), however, how much is a Cancer-Pill worth?"
Clearly Bitcoin is like cancer-pill - and we have already seen thousands of new coins (cancer-pills) appear. Eventually their price will be almost zero.
The full explanation can be found here:
http://www.mrmoneymustache.com/2018/01/02/why-bitcoin-is-stupid/Those social defaulters who are misusing bitcoin for their self interest like using bitcoin in engaging many illegal activities like in selling drugs, explosives, money laundering etc, are the real cancers and these are the people who are spoiling the image of bitcoin and bitcoin legalisation all over the world is the cancer pill to all those cancer people and I dont think that bitcoin is worthless as bitcoin has always proved its worth by making its existence since more than a decade and now helping millions of people around the world in getting their jobs and I dont think that bitcoin is worthless.