"It's very common, but seems to be even more common at the new terminal."

The reason they didn't do it at the old terminal is because at this "logistically challenged terminal" (understatement of the century) it was impossible to do powerbacks because there simply was not enough room.
Furthermore, powerbacks have to be FAA approved before an airline is allowed to perform them at any one particular airport.
Also, you won't see any powerbacks during heavy rain or snow in order to prevent injury and/or damage.


"Less ground people working = less tugs in use, and less groundpeople to signal the plane into "brakes up" at the gate."

Less tugs yes, less groundpeople no.
It takes the same amount of people. In an ordinary pushback you need one person in the pushback tug and two wingwalkers. In a powerback you need one marshaller directing the pilot and two wingwalkers.