I've worked at a DevTools company and been the CEO of one too. Here's my thoughts: I agree that they need to be open source. But that makes it really hard to make a successful business. Sure, there are examples of success, but also many examples of successful open source tools never becoming successful companies. The most famous example is Sendmail (where I worked way back in the day). They took millions in funding a…
This is what exe.dev is doing. Their open source devtools (like Shelley) sit on top of their hosting service and could be self-hosted. But they aren't open sourcing the software they use to run their VM hosting service.