That comment makes untrue claims and cites no sources. The claim about multi-million dollar jackpot winners is a viral meme that keeps making the rounds despite the people with the actual stats repeatedly trying to debunk it. It is not true that a huge percentage of winners go bankrupt.
I imagine that it's perpetuated by the myth that people who make a shitton of money "legitimately" (ie getting insanely lucky by inheritance, investing in a moonshot, or both) are somehow magically blessed with the wisdom to handle money in a way that commoners are not. Plus a dash of cope for all the people who will never touch that amount of money. Assurance that even those who gain a lot will be no better off (or worse off) than them.