MSTR is issuing stocks and debt to buy bitcoin, which means that those bitcoin belongs to MSTR stock and bond holders. Before ETF’s it was a proxy to get access to bitcoin so his model worked. 
Now there is no point in buying or holding MSTR as ETF’s are much more superior than a company stocks. It’s more better collateral than a company’s stock. 
Saylors infinite money glitch model only works if people keeps on buying his stocks and bonds, that’s the reason he keeps on shilling his company on news interviews. I haven’t seen any billionaire going on news interview that much. 

 There is no maintenance cost with his stock vs the ETFs fees. I'd rather buy and hold bitcoin myself, but I'm far more interested in the example Saylor is setting for companies than the ETFs, which are yield harvest structures for the companies selling them.