1. Lack of knowledge about Bitcoins, uneducate People only saw the negative sides of Bitcoins.
2. Some of them say negative feedback because of their experience on some sites about Bitcoins, because now a days Bitcoin are popular but there are many site will scam you if you are spontaneous to invest in not trusted sites.
If you see something wrong, educate them on the right thing. those people who do not understand crypto in detail but provide wrong or lying education are truely exist. this is nothing new. sometimes there are also public figures or someone who is an expert in the field of economics or trading also sometimes still gives the wrong education about crypto.
Cryptocurrencies are not known 5 years ago here in my Country so that mnay people uneducate about crypto and some of them will scamm so that they not trust Cryptocurrencies but now many successful in Cryptocurrencies and it is became popular now in many countries