Out of the thousand of projects many are indeed scammy. Likewise, many are serious projects, and a few like BTC are paradigm changing. Maybe not to you, the majority western (very) well off reader with a stable and sorta not corrupt governance, but to the millions in this planet where they are forced into never leaving poverty by dictators, oligarchs and crony politicians hyperinflating their life savings or seizing assets due to religious/racial/class lines (much of South and Central America, Africa, the middle east, etc) its a godsend.
Hacker news really should know better than these blanket statement smears. Its either bitterness, ignorance/privilege or paid shilling propaganda. A much more serious problem in the world than some exit scams by fly by night crypto scammers.