> Why Bram built his own language [...] I don't really understand.
What language would have you chosen in 1991 instead of creating vimscript? The vimscript language is a very natural extension[0] of Bill Joy's "ex" language, that was used in vi since 1976. The history of vimscript is not weird, it's just a fairly natural continuation of existing practices. Vimscript9 is a least-friction update for modern times.
I should have written I don't really know anything about.
According to your link scripting was only available from '98, at which point Lua and Python were already around, but then I don't know how viable that would have been. Funny you say that about ex, because I find running ex commands from vimscript the most clunky thing about it.
In my opinion the least friction for the ecosystem would have been to follow neovim and adapt Lua.
What language would have you chosen in 1991 instead of creating vimscript? The vimscript language is a very natural extension[0] of Bill Joy's "ex" language, that was used in vi since 1976. The history of vimscript is not weird, it's just a fairly natural continuation of existing practices. Vimscript9 is a least-friction update for modern times.
[0] https://en.wikipedia.org/wiki/Vim_(text_editor)#Vim_script