[Fede_V]

Sure - and I agree with all that. The issue comes with the circularity of the reasoning:

- People who are a good cultural fit don't mind working all the time

Therefore:

If someone minds working on week-ends - then they weren't a great cultural fit. It's almost Calvinist in its logic.

As you said, there's absolutely no problem working on week-ends when it's needed, or getting really caught up in an exciting new tech and spending evenings getting it up and running. However - when this become (implicitly) expected as a marker of good cultural fit, you've basically placed it as a burden for everyone.