imho its because this simply isn't an actual problem worth spending time and resources on solving. It irks critics because it doesn't fit into the narrative of trying to discern the internal rational-actor brain of a anthropomorphized corporation. It irks engineers because we like to pick one and make it the best. But for google... shrug... let them both keep going, see what happens. They've got plenty of money to pay for both teams, and consider what they're working on important enough that it doesn't hurt to have a plan b. Even if you're not sure which is A and which is B.
If they just rename the browser "Chrome" (or "Chrome mobile"), it would be pretty good for branding and making Google seem less fragmented.
On the other hand, a lot of Android's userbase is less tech-savvy who may not make the connection. "Browser" is pretty obvious to what it is.
I like to think that the lack of answer is telling. Could Android's APIs be ported to Chrome? Could Chrome live as an Android application? Could NaCl have something to do with it?