I am not sure what you want to say with your comment? That you move to another language as soon as there are breaking changes because you are invested as a user and therefore dissapointed? While this is a valid reason, it's just the way languages work. Some prioritize getting the language right and other backwards-compatibility. If your argument is categorical (languages that make breaking changes are bad) then indeed, python is not the language for your use-case (which is fine btw!). Java never made breaking changes, but it forced a massive limitation in the design-space for some language features (generics for example) for which it still pays a heavy price years later.
Also I think you're too harsh on the analogy, most of the time there's a way to write python2 and 3 compatible code, so which means the transition can go smoothly.
This is a bit and oversimplified, but it also seems a bit weird, to me, to respond to a situation of "man it's going to be really annoying to rewrite all this code" with "You know what sounds like a better option? Rewriting all this code!"
I think a fairer interpretation of the situation is "Well, we have to rewrite and test all this code anyway, so the barrier to picking another language to go forward with is quite low right now."
That's a corollary to this, for sure, particularly if there's another language that would be more appropriate. That said, the OP seemed to be moving on primarily out of annoyance. Assuming that's the case and Python is the best language for the project (keeping in mind things like "I can hire the same quality people who WANT to work in this language), I stand by my (still slightly tongue in cheek) position.
A question comes to my mind on the desires of developers to work on Python projects. Would it be fair to say Rust or Go might have more desirability these days? The WANT question makes me think this is a bit more than simple annoyance but provides an excuse to travel to greener pastures.
It’s a bit less absurd when the person gave the reason that they feared a similar breaking python release in the near future. This might still be incorrect of them, but to me anyhow it’s not strange or silly reaction.
Also I think you're too harsh on the analogy, most of the time there's a way to write python2 and 3 compatible code, so which means the transition can go smoothly.