I think those who talk bad about cryptocurrency are either ignorant or traders. There are thousands of people in the world who are not related to cryptocurrency in any way. They basically start spreading bad words about crypto after hearing the name of cryptocurrency from someone else and hearing about its disadvantages. As a result, many ordinary people start saying the same thing. Which happened to me too. If I had not joined the forum, my misconception would never have changed.
Majority of people who criticize crypto are either ignorant or people who are filled with regrets of not using their opportunities rightly when they had it to buy at a cheaper amount. There are tons of bitcoin critist who are now massive bitcoin holders with FOMO any potential time they have now to accumulate more. So no matter how much people criticize bitcoin, at the end they'll all come to a conclusion that is not what they taught it was. Bitcoin is not a shit project that we should expert a serious dip of crash
Ignorant people don't criticize crypto like those who are regretting not telling action when they're supposed to. Most of them get a sense of satisfaction from badmouthing what they don't benefit from. Another reason is that most fake projects of crypto backing have seen people lose lots of money including scan investment platforms who uses wallet drainer sites to steal funds from wallets connected to it. You can't blame some of them for criticizing crypto owing to their bad experiences, but their greed always leads them to their ruin.