The challenge is that Steve Jobs got it right. It's a niche product that compliments the core phone and notebook. iPad is only superior to a mobile phone and a notebook in 4 of these 7 functions (reading, photos, video, games), and none of these 4 functions have grown or changed in a manner that makes upgrading an iPad a necessity.
It's not some sign of disrespect when analysts say that there won't be huge growth in a category where a 7 year old iPad Air 2 does an identical job of large screen reading, photo viewing, video watching, and gaming.