I wouldn't say keeping it private and that article are your only choices. You should absolutely disclose that you had a cofounder who didn't work out because he

I wouldn't say keeping it private and that article are your only choices. You should absolutely disclose that you had a cofounder who didn't work out because he turned out to be incompetent. Hiring a cofounder is tough and people make mistake all the time, they've seen that before. But sharing that specific article is a mistake, instead just stating it without emotion is probably better. I know it's tough, I was in a similar position with a cofounder who really didn't work out and I really resonate with that line "I do miss that naive me though, there is something wonderful in trusting your fellow man that I can never quite regain, which is a shame.". My experience also made me lose that bright sunshine of naivety and easy trust that I had and for a long time I was incredibly bitter about my ex cofounder. But, it's not a good strategy to be publish it with a wording this emotional, instead just being very matter of fact about it, describing the main issues in broad terms is enough.