> Unless said rogue apps are written by Google, how do they help Google's business model?
Tracking information is a revenue stream. Revenue pays for content development. Content sells apps. Google profits off app sales.
Therefore, Google has a disincentive to do anything about the transparent (read: user doesn't know it's happening) third party collection of tracking information. Particularly given the noted disinclination of Android users to purchase apps, relative to their iOS peers.
An alternative take on this is that Google has more of a vested interest in securing what data they do collect and making sure it does not leak to any other party. They've generally been ahead of the curve in terms of privacy on the web, such as keeping rogue CA's in check (remember the CNNIC fiasco?), pushing for HTTPS everywhere, or making 2-factor authentication more usable.
Unless said rogue apps are written by Google, how do they help Google's business model?