Kroah-Hartman removed the code in December, noting that Android drivers "are no longer being developed and the original authors seem to have abandoned them".
In a blog post on Tuesday, Kroah-Hartman explained his motivation, saying: "No one cared about the code, so it was removed". He said Google's decision to effectively create a new kernel branch meant any drivers written for Android hardware platforms cannot be merged into the main kernel tree.
"Because Google doesn't have their code merged into the mainline, these companies creating drivers and platform code are locked out from ever contributing it back to the kernel community," he wrote. "Companies with Android-specific platform and drivers can not contribute upstream, which causes these companies a much larger maintenance and development cycle."
For more on this story, read Linux dev explains Android kernel code removal on ZDNet UK.