Default please port the latest update of google maps (a.k.a maps8)

hi guys as latest update of Google maps is rolling out.
why Google why
as we all know that jellybean 4.2 has the biggest share in Google's pie.
so why the 4.2 is being isolated from maps 8
Google maps 8 works on api level of 18 whereas 4.2 is 17.
thank god that we have xda .
please geniuses . help me
can someone port maps 8 to 4.2
hope xda will help me