It doesn't look like this person has some sort of power to trigger a negativity trend and cause a huge drop in the price. There are a lot of people speaking against crypto every day, and we don't have any problems. Some random internet celebrity is not going to cause anything.
That's right. Maybe followers of this guy will have influence, but as you already noticed, there are a lot of different opinions on the internet about crypto currencies and each of use decides himself to which one to trust and to which not.