RE: The 213,500 BTC Bulgaria sold in 2018 are now worth 78% of its public debt 🙈

Reading about this now, it really seems unfortunate. I would not blame them for the decision, though.
Even if they would've expected Bitcoin to go up in value over the years, it still could be a good idea to sell it, depending on the investments they made with the money.
Of course, it would be great right now if they could pay off such a large amount of their current debt. It's possible, though, that they made some investments in 2018, which resulted in a lower debt over the years, so it's possible they actually "prevented" more debt than only the 1-2 billion dollars their Bitcoin was worth at the time.