Buying lottery tickets is buying 'hope insurance'
From my own perspective, there are a few different ways in which I could become fabulously wealthy, or at least much more financially secure than I am now. I could create or work for a hugely successful company. I could make a killing in real estate. I could win second place in a beauty contest. Lots of different things.I try my best not to be materialistic, but there are times when I see beautiful homes or fancy cars or $650 Prada shoes and I think "I could so totally enjoy that someday". There's at least a little bit of hope that I could, someday.
There are lots of people out there who, without the ability to buy lottery tickets, would feel they have no possible way to become fabulously wealthy (even if that feeling isn't strictly correct). For these people, there's no sense of hope for breaking out of where they are, and the absence of hope is very painful. Spending a few dollars a week on lottery tickets to keep that hope alive becomes a sort of rational purchase. People aren't actuarial robots.
I'm not saying that I think that buying lottery tickets are a good idea, or that government-run lotteries aren't a form of abusive regressive taxation, but the conclusion of the linked article that people are still poor because they keep on buying lottery tickets is naive and condescending.