It would be better if NOAA used kilopascal (an actual SI unit) instead of millibar, but I guess the conversion is not too bad since 1000 mbar = 100 kPa.

The NOAA data isn't consumed solely by scientists though. I'm sure millibars were chosen as the metric measurement of pressure because people actually use them, such as mariners.

Just the other day a last minute task at work put me under 500 millibars of pressure.

I'll show myself out.

"Oh wow, air pressure fell to almost zero, a person would suffocate in ther... Wait a minute, the ground unit is 940! This is a 6% difference!"

Sometimes ground units reflect ground truths, even if the scale doesn't actually hit zero.

Yup, this is also why I like the metric version. With inches of quicksilver it's hard to know where zero is.