What carrot? A carrot is an incentive. Google didn’t embrace the tablet format until very recently, in the grand scheme of things. They haven’t offered devs any special deals that I’m aware of — say a revenue split from the play store or paying them to deliver a tablet version of their app — so they didn’t incentivise devs to focus on Android tablets.
iPads have dominated the market for so long, and remain a fairly predictable and consistent device to develop for, so… why would an app developer have poured time into an app for Android tablets in years past?