Well, Excel has a lot of common use-cases around processing numeric (and particularly financial) data. Since some locales use commas as decimal separators, using a character that's frequently present as a piece of data as a delimiter is a bit silly; it would be hard to think of a _worse_ character to use.
So, that means that Excel in those locales uses semicolons as separators rather than the more-frequently-used-in-data commas. Probably not the decision I'd make in retrospect, but not completely stupid.
Every time you cat a BSV file, your terminal beeps like it's throwing a tantrum. A record separator (RS) based file would be missing this feature! In other words, my previous comment was just a joke! :)
By the way, RS is decimal 30 (not octal '\030'). In octal, RS is '\036'. For example:
$ printf '\036' | xxd -p
1e
$ printf '\x1e' | xxd -p
1e