OpenAI decided keep it for themselves, their tech was impressive but they didn't have a killer app and they tried to prevent the inevitable by restricting the use of their machine.

StableDiffusion might be inferior to DALL-E in some aspects but they build a community with full access to the tooling and that community is much more likely to find a killer app for this impressive tech.

It's kind of ironic that OpenAI is losing out due their closed ways and desire for control.