Everyone has a few. What are yours?
My main ones are - unit bias has held back BTC's progress in the mind of the public.
Bitcoin will never see widespread use as a currency.
95-99.5% of the world does not want to be their own bank. And a decent proportion who do want to be, should not be.
My unpopular opinions:
1.Bitcoin is only a bunch of code and the creation of that code (mining)wastes electricity.
2.The only incentive about using bitcoin is the possibility of a future price increase.
3.People will never fully adopt bitcoin,because they want to be slaves of the government protected banks.(it keeps their false sense of security)