When big boys enter the picture, the rule has changed. Bitcoin then becoming a fprm of investments, and no longer the original vision of satoshi, iguess its really inevitable, specially during the 2016-2017 when it peaked at around$20,000. It become a speculative asset, and others tske that as a opportunity, trying to make quick bucks, or even putting thier whole life-savings hoping to become rich.
This is a common occurrence as you said since 2016/2017 especially the 2017 period that gave birth to a lot of ponzi investments using Bitcoin as a base currency and this has totally dample people's mind about Bitcoin because most people now thinks that everything about Bitcoin or cryptocurrency is associated with ponzi scheme which is wrong. The best we can do to correct the situation is by exposing the good side of Bitcoin to them and discouraging them from joining unvarified crypto investments