Good TVs are very expensive and people tend not to upgrade them very frequently (10+ years seems commonplace) This would give Apple a 10+ year lock-in to their

Good TVs are very expensive and people tend not to upgrade them very frequently (10+ years seems commonplace) This would give Apple a 10+ year lock-in to their ecosystem. They could then sell iPads as controllers and additional displays. And if the computing power in them starts to get underpowered for what people want to use them for they could sell add-on boxes connected via Thunderbolt that would have as low latency as anything inside the TV housing.