I've personally learnt not to blame people like this when ever I come across such tweets or post where ever, and I also have learnt not to laugh at them because we never can know, they might be doing really well for themselves right now while most of us are still here grinding, alot of them may have turned back to later buy into bitcoin when they discovered that its not really a mess as they had assumed, and today, they are living very large and not making noise about it online.

As a matter of fact, humans make mistakes, we all make mistakes, and for those who knew about bitcoin back in 2009, 2010, 2011 up to 2015 and never believed in it, that could be one of the mistakes in life, there is no need throwing shades at them because mistakes is something we all are guilty of.
And also try to put yourself in their shoe and consider how timid bitcoin was back then, it's possible you also might not have believed in bitcoin back then when it had very little chances of succeeding.