That's really the only reason to migrate off OpenWrt. The reason Raspbian isn't the base is because:
-- It is massive, multiple gigabytes instead of 32 megs. I can't host giant preconfigured images so it would add more steps to the install process.
-- There is no web config tool for configuring wifi or network settings
-- Variability. Knowing exactly what is in the firmware on everyone's devices makes troubleshooting less painful.
-- Slower boots! Although this isn't as bad as it used to be.
There's also the complete rewrite of all the existing linkmeter code and web pages (wrinkles nose).