Like I've said in these comments, I'm constantly surprised by which settings people change and which ones they don't, so differing opinions on exa's defaults is nothing new. exa shares my opinion of wanting to see thousand separators and byte suffixes by default; ls, on the other hand, has no opinion because with file sizes that small, it didn't really have to choose what the output should be like.
People have said that in scripts you'd want to just output the file size in bytes, and they're right, otherwise the numbers won't sort correctly. If you're writing a script, though, you're going to be taking more care than if you were just wanted to list some files. I've lost count of the number of times I've listed a directory, given up trying to count the digits of the file sizes, then re-ran the command with `ls -h`, but I've never written a script without thinking about what the output should be like.
Actually, many of the utilities that output in human readable format do so in a way that's also sortable through sort's -h option. It might be worth making sure you have a mode that outputs the same way so people can easily utilize sort. That is, K/M/G instead of Ki,Mi, Gi. Unless sort ignores the second alpha character when using -h and it still works, then no problem. :)
Edit: Actually, I just tested, and at least as of the sort in coreutils 8.4, it recognizes both forms, and actually dies with a warning if you mix them, so you're all good!
# echo -e "100Mi\n100Ki\n10Mi\n10Ki" | sort -h
10Ki
100Ki
10Mi
100Mi
# echo -e "100Mi\n100Ki\n10Mi\n10K" | sort -h
sort: both SI and IEC prefixes present on unitsI think your perception of filesizes is slightly skewed; "nine or more digits" means roughly >=100MB. Disk images, software, and videos would be in that range, but probably not the average MP3 (100MB of 320k MP3 is over 40 minutes), and I don't think I've ever handled a "word processing document" more than a few dozen MB --- and even that would already be many hundreds of pages.
Of the files sitting on my desktop at the moment, which is not necessarily representative nor typical but covers a wide range of types (pdf, mp3, zip, exe, jpg, mp4, ...), slightly more than 10% are 10MB or more (8 digits), ~15% have 7 digits (1-9MB), and the rest are below 1MB (<= 6 digits).
Seven digits isn't quite as bad, but without thousands separators it's bad enough.
Even then, most of my documents are quite a bit smaller, as I have a tendency to write my documents in wordpad instead of office, and then save as rtf or txt.
I'm not sure why I said nine, seven is what I was thinking of.
Human readable units helps quite a bit with this, and I think that makes it a sane default. As long as you can specify you want to see bytes, and the sorting is done on the actual byte value, there's little lost because the majority of the time it will help rather than hurt.