I agree with your first sentence that earnings from bitcoin is more higher than the interest from banks, I also have my money in bitcoin instead of bank for that reason.
And in your second sentence, it is true that some people have lost their money when they bought them at $700 and after a month saw the price at $600 and $580 etc, but if they hold for more longer they can recover their loss and if they know about trade then they can start trade and can recover their loss sooner.