[Q] Noob Question topic

I do not know, how silly is my question..

Why no one is attempting to build Gingerbread/Jelly Bean roms for Moto E.
I feel there are wide varieties of ROMs available in GB Version, like Mokee, Joy OS, MIUI, Lewa, DX, Sense3, etc., which will be a real visual treat for eyes.

Just sharing a thought flickered in my mind..