Or, I suspect the quote is mistranscribed or was spoken with a mental "shortcut" and should be: They’re not [in]capable of understanding a brilliant language,

Or, I suspect the quote is mistranscribed or was spoken with a mental "shortcut" and should be: They’re not [in]capable of understanding a brilliant language, but we want to use them to build good software. i.e. they're smart people, but we don't want them to focus those smarts on the language itself, but on writing software with the language...