* Alphabet has 33+ letters, so there is no space left for programmer's favorite symbols on layout: @#$^&{}[]|~`<>. Yep.
* In Math variables' names traditionally are Latin/Greek letters, Cyrillic is used only when teaching kids. Again: switching layout all the time? No, thanks.
* Words are simply much longer. And I mean much. In English even short words tend to become shorter (variable -> var). In Russian there is simply no such pattern exists. `var-set` -> `установить-переменную`. `var-get` - `получить-переменную`.
* Words are stable in English morphologically. e.g. `last-msg-delivered` - `last-msgS-delivered` -> `последнЕЕ-сообщениЕ-доставленО` - `последнИЕ-сообщениЯ-доставленЫ` - if you change gender or from singular to plural etc you should change few words in a row.
Seriously, it seems to me like trying to make things more complicated.