That's someone who doesn't know what words mean.

When a building is built, the scaffolding isn't an immutable part of the final product.

Well if we're being anal about the metaphor, in construction and renovation, the scaffolding eventually goes away. Scaffolded code rarely disappears entirely; some of it usually sticks around.

To be perhaps even more anal, after construction scaffolding is taken down, stored, transported to a new project and then used again.

And it's made of steel, not bits.

If there are no bits then what're all the pieces linked to?

Then that makes it an inappropriate word for both uses.

It’s a little ambiguous with Entity Framework. There is no rule that says you cannot change the resulting code. If you want to continue with Code First, that is a totally valid approach, there’s even a subsection on that.