I'm pretty conservative in my predictions and just think there is a lot of free money on these sites. Maybe that just supports the sentiments of this article and most of the negative comments on this post.
There are certainly cases where I got run over by the steamroller picking up nickels, but in general that's few and far between. A good example is getting trump losing the 2020 election at 90% after the election in November. If you find those types of markets and compound the earnings it's a pretty nice savings account.
I've also been burned by insider trading and vague rule interpretations but at this point, you chalk it up to the nature of prediction markets. I now try to stay away from markets that are more manipulative (e.g. mention markets).
I don't understand the hostility to prediction markets. There are definitely hedging opportunities and we're all adults.