There are major vendors supporting the free alternatives.
Also, totally fine for commercial vendors to what they feel is best, but would be better if they were upfront with it at the beginning versus changing things after taking thousands of contributions,
I get your point and it's valid. At the same time, why would Docker be an exception?
The Docker Desktop licensing fees range from $5-$24 USD per month, which translates to $60-$288 per annum. Is this a good value for a rarely used GUI required on Mac (and presumably Windows? I have no experience to offer here) for an otherwise FOSS platform?
Having dabbled in machines and a bunch of other things there's a ton of tooling that is not paid you make it yourself it's called jigs and fixtures it makes up a very large portion of what people do. That and consumables such as wood metal screws carbide tips etc. The place your analogy really falls down is what percentage of tools are monthly subscription fees versus a hammer you buy and then last 40 years. Sure people who buy a Haas CNC machine will probably buy a support contract on it because that is also essentially insurance and allows them to swap the parts out quickly because it gets the repairman's attention and it allows them to more quickly upgrade while they're running their business but it is also essentially another consumable.
We also live in the world of software where copying bits has zero actual cost other than a minuscule amount of power on the provided fixed infrastructure that we've already paid for. So it's in no way unreasonable for people to be upset or annoyed about paying for something that was free for almost 10 years that is mostly a UI configuration tool where there isn't an open source alternative because for 10 years someone gave away one for free that was essentially open source and then decided to start charging for it.
It's also completely reasonable that very large companies that are already paying this cost have done the math and decided you know what it may make sense for us to just build this ourselves and give it away to everybody else since we're building it for ourselves anyway and we get the ecosystem effect because that's cheaper than paying the people who decided to start charging for a thing that we all thought was going to be free.
To make it even worse in the past people were probably contributing to docker thinking sweet this works on Windows Mac and Linux and these people are great and they're keeping it free for everybody. Those people contributed to the docker ecosystem under a false premise which is now changed. Luckily I didn't have a chance to make a contribution to doctor because my large company did not let me but if I had I'd be very pissed.
This switch is just going to move developers who only need basic docker features to free software.