No one can predict the price of the coin. Even the best traders in bitcoin sometimes fail. Though you lessen the risk and maybe come up a good strategy on trading.
Yes, that is true no one can predict the price of any coin for short term like daily basis but experts can analyze the price of coin for a long-term point of view based on coin features and its usage in the future. That's why I always say people don't go for day trading but everyone wants a fast money and want to become rich faster so they choose to go for day trading and will realize that it is difficult only after losing some money.
We can't blame the people who is doing day trading. They are considered as a high risk takers. Some of them are successful doing it, some of them fails.