Taking a brief look at the financials it looks like they have been cash flow positive the last few years except last year and that was only because of a very large "other income expense". No idea if that was a one time thing or not without digging deeper, but the company appears to generate a profit outside of that.
Irregardless, perhaps he's making his company a bitcoin holding vehicle. He can sell more shares at higher prices to raise capital any time he wishes. I go agree that it's a unique situation and at some point he won't be able to do these debt offerings, but for now, there is plenty of demand for them.