I agree, that's cool, but some contractors take it a step too far and bid projects on the assumption that they can replace unfamiliar techniques, materials, and

I agree, that's cool, but some contractors take it a step too far and bid projects on the assumption that they can replace unfamiliar techniques, materials, and design details with alternatives they can do more cheaply and easily, and then they make themselves into a problem much later in the project when the client doesn't agree to the alterations. I think it's something that contractors even do in good faith. They read drawings and think, "Oh, I know a lot of ways to speed this project up, they're going to be super happy with my bid." They can see it'll be easier if they use a different material, move a door twelve inches this way, move the electrical to another wall, replace a difficult detail with an easier one, etc. They've probably worked on projects where those details are chosen without much care, and the client is delighted if they can speed up the project a bit by changing them.