Umm, doing fine? If they had/have a consistent cash flow that enables them to make a fixed home mortgage payment (sorry for those who don't have fixed payments), then all that makes sense and isn't super risky. I absolutely took advantage of a lower interest rate and a much increased home valuation to handle a few things: dropping PMI, and then leveraging up to 80% of my home value with a reasonable monthly payment to get dollars out. Those dollars partly went to some home improvements (new roof, new heat pumps), paid off some higher interest rate debt, and absolutely bought some bitcoin. I don't regret any of that, even though I think when I was doing those buys, bitcoin was around $48k USD. And I haven't had to sell any of it.
Now, doing the same thing right now, at double the interest rate, almost double the house payment? Not the same scenario. Going past 80% of home value, where you are paying PMI? not something I would want to do. Taking on a mortgage tied to rising interest rates, or with a monthly amount that would already be uncomfortable to satisfy based on your income cash flow? Nope. Not discounting your income a bit based on the screwy job market, where you are potentially more likely to be laid off from a tenured position, or are trying to ladder up from position to position between various small companies? Bad idea, your incoming cash flow may be interrupted for months at a time.
So then, for some, it may have been the right idea. I don't mind taking on some low-interest debt, or maintaining low interest debt, to buy bitcoin. That is all MS is really saying and doing. Overall, you are trying to accumulate more bitcoin today, and pay for it by maintaining debt over time. I do this in the smallest of ways anytime I put something on a credit card instead of paying for it with cash, because I already know any extra cash I have sitting around is going to buy bitcoin, not pay down credit cards. That means I need to be comfortable with my monthly credit card payments - and by comfortable, that means I need to be able to make them even if I'm a little short on income for a few months, or if they go up by 25%, even 50%. Or both. I need a plan for that. The last option in that plan might be selling bitcoin, but there should be many options in front of that.
I have not yet had to sell bitcoin to cover debt. I did sell a little bit when I tried to get paid 100% in bitcoin, because I still had to have US dollars to pay bills. I've been tempted to sell some at other times, but converted debt to different forms (like personal loans, for example) or shifted things around so I wouldn't need to. I'm not going to say never sell, but there are other options that may be out there. One of those options may be your house, and changing how that is being paid for. Every situation is different, with different options available.
And I don't know how I will react when bitcoin spikes the next time. Or the time after that. I may sell some, and shift around some debt before buying back the bitcoin. Depends what is going on with my cash flows at that time, I guess. I'm thinking about leaving my current career, even - where I am at with that might make a big difference in what decisions I make. Maybe I use some bitcoin to finance my career change. Maybe I won't have to.
Dismissing (or shaming) an idea that would be risky for one set of circumstances, or even many sets of circumstances, is not leaving yourself open to possibilities that may make sense and be much less risky for another set of circumstances. You are definitely not in Michael Saylor's shoes, and don't have the same opportunities at your disposal - but you can definitely be as open-minded and strategic in the ways you stack.