I agree, it's silly. But I also think it's silly for people to continuously complain about this. All the phones that are supposedly being dropped (it's still not 100%) are over two years old. That's still a longer life span than most Android devices and all of those devices got any Windows 10 update almost immediately as it was available. Even the most expensive flagships usually have to wait months after the initial release date before they get a major update.
Yes, I think it's ironic that the update that dramatically improves performance on older devices is the update that drops support for those same older devices. I also think you got what you paid for when you bought that phone. Almost any Android phone wouldn't have gotten the same treatment. Yes, I think any one of those devices are perfectly capable of running the Creator Update and running it well. But that doesn't mean Microsoft is obligated to update those devices. If support for them really has been dropped, I'll swallow my disappointment because it's what happens to any phone over time.