Because that's GP's attempt to differentiate it as it cannot be done any other way ;)

Physical things are obviously subject to physical laws. With software, things may be less clear. Sometimes they are not. The key part of engineering that's highlighted by such cases is that mathematical models are relevant. This is why an engineer sometimes has to say "no, that won't work".

Software is subject to physics and math/cs laws

>This is why an engineer sometimes has to say "no, that won't work".

But similar scenerios can occur in SE world too, so what does it even mean? like some unsound design of distributed system

Then if you see yourself as a professional and if you have a strong character, you say it. If you're a real engineer, you and everyone knows this is part of the job, but if you're a SE, generally speaking you're going to meet resistance. Your resignation letter should be ready in your pocket.

The surprising thing to many of us is that the "software engineer" title has been specifically associated with deprofessionalization of the job and the view that is moving away from true engineering. See the Dijkstra link I posted elsewhere in this thread.