Good debts - loaning money to purchase something that would appreciate in value over time. Real estate, precious metals, commodities etc.
You have a point, OP because good debts can also contribute to one achieving wealth and happiness, helping to obtain something useful. But it can become bad when you take on too much that you can't handle or even pay back. Before you know it, it has become something you wish never happened, a big loss for you.
They say poor people have bad debts and rich people have good debts.
Is not really true, as a matter of fact it all depends on the individual, poor people can have a good debt that can produce a positive result at the end and a rich man can have the opposition, is just a vise versa. We can't just say poor people have bad loan because they're poor and rich have good loan because they're rich and they have it all to make things right, no, I disagree.
One of the popular pieces of advice you'd hear in the Bitcoin space is to never borrow to invest in it.
Despite the volatility, our hope is that Bitcoin will appreciate in value.
Would you classify borrowing money to invest in Bitcoin as good debt or bad debt?
It has never been proper to borrow money because you want to invest even if it's Bitcoin, never forget that in business you just have to put it at the back of your mind that is a 50/50 thing, you don't have to win or gain always so that how it is.
As for classifying borrowed money to invest in Bitcoin as a good or bad debt, I'd say no to that. Borrowing to invest on Bitcoin can backfire, anything can happen so I don't support such.