The hyphen it really handy to distinguish letters of different scripts. There are some scripts that can work with short script suffixes (a for arabic, hb for hebrew, d or dv for devanagari) but I need a system than works with a lot more scripts. That requires much longer names. If you need to make ligature of those it gets really long and difficult to read: e.g. lepchaBa_lepchaOoVowel. Compare that to ba_ooVowel-lepcha. I added the script to the end and only add it once per ligature. To still being able to process the names by code (to generate Feature code), I need to have a separator glyph. The specs only allow periods and underscores. Both already have a meaning. So I needed to go out of the spec and looked for a glyph that would make the most sense and add mechanisms that generates production names when writing final fonts.
That mechanism is the basis for support for the non latin support in Glyphs so it is not going away. So we need to find ways around the append problems.