Is it possible to change the language to be simply English?
No, it's not possible I'm afraid. For our forum engine (phpBB) there are two 'english' language packs available: British English and United States English. There is no simply 'English'.
Also you are not correct by giving 'French' as an example, as we currently have 'French (Standard)' installed, while there is also 'French (Ortograf altèrnativ)'. Similarly German - we have currently 'German (Casual Honorifics)' installed, while there is also 'German (Formal Honorifics)'.
Honestly - it's only the matter of naming convention (the differences between those language packs have no meaning in our forum level of interest, they matter only on philology and similar language-experts forums) and really makes no difference in using the forum. If it hurts your honour then all we can say is apologies, but please take no offense and just forget about the naming of language pack.