Same for "2.4 GHz wireless network" but it's supposed to be 2.4 gigahertz if fully spelled. I suppose there is a logic behind but it's not obvious.
Other order of magnitude indicators are capitalised to distinguish them from their smaller counterparts (millimetre/Megametre).
Wikipedia states that the distinction is because units named after a person always start with a capital letter. I've always assumed Hz has to be capitalised to prevent confusion with the hecto prefix (hHz being 100Hz). I don't think there's a unit or order of magnitude that's abbreviated to `z`, so in theory "Hz" could just be "H",
I think Hz is more readable, but that's probably because I'm used to it.
Note that m is milli and m is metre; overlap hasn't stopped collisions between prefixes and units.
> "Hz" could just be "H"
No, H is henry (for inductance). https://en.wikipedia.org/wiki/Henry_(unit)
I don't know, but it seems to me that if they wanted to be scientific they wouldn't be seemingly arbitrary in the capitalization rules
In the end the reason for the weird capitalization is just to avoid situations where that ambiguity will occur.