Nearly half of Twitter users believe that the price of bitcoin will not reach $ 50,000 by 2021
1. It's easy to predict any price. That doesn't mean the price will care about that. Predictions are cheap and useless.
2. You started with a bold sentence which you didn't prove. I can tell that it's more likely that more than half of Twitter users don't know what Bitcoin is or don't know (nor care now) about its current and 2021 price.
You are right. This was just an article about the data of a poll that only people guessed about.
Also, your second sentence is correct. Today, Bitcoin is not so well known that we know who to ask.
(Believe me, not even half of my academics know

)