> People don't really think "my priority is 8.3 inches"

I have 12.9" iPad Pro, my priority was thunderbolt and screen size, but mainly screen size (battery life is given on Apple devices).

I also have iPad Mini where my priority was...bigger than the biggest iPhone, smaller than regular iPad.

> The killer use-cases for tablets seem to be drawing and media consumption, but not only is drawing not a huge market, these two aren't at odds. Both are better with a better, bigger screen.

It's like all-season tires, does not exceed in any particular field. I use my iPad for casual CAD with 3d printing in mind, it works great. I also use it as a bedroom screen on stand by the bed. Can two separate devices do a better job? Yes, but I don't need

> For laptops the buckets are portability and performance.

iPads not bucketed like this because you're not buying iPad for performance.

> I think the iPad's lineup could be simplified to just one model, but I understand Apple want's to have several for marketing and price-ladder delineation, like it does with the iPhone

Sure they can. This would lead to less overall sales. Right now 11" buyer have whole 3 feature set selections to choose from. I'd get rid of Pro, but not everyone needs 11" and Air features.