I suppose you're right. There's no real way around it. I'm assuming there's been a lot of face to face meetings between Saylor and coinbase. It's just shocking that as a "bitcoin company" they haven't innovated their own storage protocols. 

Aardvark

Stacker_Stocks

MicroStrategy has cut 20% of its workforce as its bitcoin buying multiplies

Totally, but when its a company handling bitcoin you will have to trust someone. At a corporate level and even more so at a public company there are factors I suspect we aren't considering. But yeah, its a lot of trust. But if they did their own custody it would be just as much trust placed in a different set of people.