1. Transactions takes hours
2. Fees are high
3. Development team sucks, uncapable solve scalability issues for years
4. Its not anonymous, every solution to make it, failed so far
5. Its centralized: who is biggest hash power owner? Who is biggest miner hardware provider? Who owns most of bitcoins? What is % of Bitcoins in coldstorage and what in exchanges ( Ye Mt Gox )
6. There is 0 economics for BTC, it just tight to USD with liquidity providers, cut that and try to value pizza box with just BTC
7. Its not store of value, its not digital gold, and it will never be 100k USD. Because it has no value. It has value only for energy probiders, hardware manufactures and random phils.
8. Its not insured, If some crap happened to your BTC, its gone.
9. Bitcoin has a limited supply, but it does not help much. Bitcoin has a code that can be amended and its enough of small group of people to work together to support that. Question really is: do someone need that hassle? No really. Bitcoin has satoshis, that currently meaningless and just nice numbers after dot, but this a very well painless way to inflate any crypto currency and its up to liquidity providers. Again it falls to point #5 and #6. Added on 24/01/2018
Such crap will never be used in payments, noone wants to support Terrabytes or Petabytes of data.
Its funny to observe how uneducated shills trying to make casual office landline phone to look smart phone.
BTC is scam of the century, stay away.
UPDATE 23/01/2018:
useless, guys the fact that some of you become reach and wealthy does not make Bitcoin useful. You wealth does not come from values that are used in propaganda.
1. Why I am still here? I believe there are technologies that are better maintained and lead than BTC, I prefer put money in something that bring value, has use-case and been used.
2. LN is panacea! Well not, so far its more dream than reality, no doubt it will be delivered in one or other way, but it will not solve all problems and so far it has more questions than answers.
UPDATE 24/01/2018:
Everyone is amazed of why I called it useless, well, recently Stripe dropped support for Bitcoin payments. This is the prove of Bitcoin being useless. Stripe was not the only one in recent months to do so. It should ring a bell.