It's common in general, unless you had requested otherwise. Depending on what type of showers you have and how tall your ceilings are, there may be other reasons they chose to do it, but certainly it is less costly, so that's probably a big one. (We went that route because our walls aren't square and ending the tiles short of the ceiling helps hide that, but hopefully that's not an issue for new construction!)

Depends on the context. Do you have photos?

What do the construction drawings show?

Tiles to the ceiling is relatively recent installation phenomena. It's always a signed off change order, for extra costs, if it was not specified in the architectural plans and section details. Your plans should have had section details that showed the details, if it was part of the project. Like this:

Agree with artemis. Recent style / expectation change and only done when specified. Otherwise - $$$ stuff only goes where it's functionally needed and no further.

I planned all my bathrooms in my new build and gave my builder the quantities I needed to complete the design I wanted, including going to the ceiling in all showers and also tiling the ceiling in all showers. I then met with the builder and tile installer to go over the design details.

We all have different ideas of what is "normal", so always best to specify what you want and not let someone else implement their version of normal in your house.

Production is somewhere from 60-72", most custom we'll plan at 96" and charge for taller unless its noted on plans or proposal.

It costs more from a ladder.

Style ques are often taken from photos of very high end projects with budgets to match.

Thank you so much for informnation. Mine is semi custom house that we paid top dollar for. We did pick the tile and paid for the upgrade but no discussion was had about the tile height. There is a window in the master bath and the tile stops in the middle of the window. I really dislike how it looks.