I am both a software "engineer", and have separate non-CS engineering degrees.

What the vast majority of us in software do is not engineering. I think like you say liability is one part, but another big part is the immense breadth of unknowns we have to deal with and accept, but never really chase down. There's no budget or time given for properly figuring out and scoping a project (for most programming), because the penalty for failure isn't so steep. It's not written in blood, so we don't dedicate the resources necessary to really engineer it.

Some programming is arguably engineering. Many parts of aerospace for example. Some of the medical devices space. But it's overall a very small percentage of total programming happening in that world.

And you know, that's probably okay, for now at least.