One thing that Bryan understands is that you can "lock" the customer in with great products and services, as well as continuing development, while also making the customer feel secure in having a way out should you turn into a company that treats locked-in customers as cash cows. The open source strategy (it is a strategy for Bryan and Oxide) is there precisely to do this: make the customer feel they can leave you, but then not.
For your deeply technical staff, having source code access is a big deal too, since it enables them to better understand the products they use.
How big is the market of sufficiently-vendor-lock-in-averse customers? I don't know -- that's not my remit. But there's the size of that market right now, and whether Oxide (and any other companies with similar visions) can grow that market by sheer willpower. I make no predictions.
What if Oxide can get the next Netflix to use their stuff instead of a public cloud?