Docker Desktop has different and obnoxious licensing requirements. If you are using Desktop and are unaware of them, you absolutely should be especially if you work for any company of meaningful size.
This part includes most serious technology businesses that have made it past the early stages:
> Docker Desktop is free for small businesses (fewer than 250 employees AND less than $10 million in annual revenue), personal use, education, and non-commercial open source projects.
That sort of license requirement on an otherwise free tool makes it easy for employees to accidentally install software that their employer is then on the hook for. In addition, Docker Desktop was available for free for years, and they only introduced the new license a few years ago, so a lot of people still have a bad taste in their mouths from having to migrate their whole team off of it. It's not unreasonable to charge money for this software, but charging money without having a way for people to explicitly opt in is tricky at best, even if they don't have bad intentions. (And speaking of bad intentions, ask any engineering or IT manager how it feels to wake up to a threatening email from Oracle because they detected that someone somewhere in your company used a product that requires a license, and the terms of their license require that you pay for every single employee at your company.)
I imagine some people also have problems with charging for software that is built on top of FOSS, but I am not especially ideological about that and I assume that Docker is at least obeying the letter, if not the spirit, of the relevant licenses.
