I think that sounds fair. The concept of being on call is not unique to software engineers. You might be an emergency doctor. You might be a fighter pilot. It's possible that some software engineers need to be on call, because they support some critical infrastructure, and that can be part of their contract.
I would say the default assumption for most software engineers should be they are not on call and the company should try to structure itself around that assumption. The problem starts it's just considered the norm that software engineers are expected to work 24/7.