How in Zeus' beard was the iPad revolutionary? It totally was not and really never has been. Evolutionary, sure. The iPod actually wasn't that good or revolutionary. iTunes was the true driving force behind the iPod's "revolution". It was a competent media player that was somewhat more polished compared to the competition. It definitely upped the specs and storage, (mainly storage) making it cheaper all around, but the true revolution came from the iTunes storefront, which before was hard to come by a reliable and trusted digital storefront with legal competitive prices. (Pretty funny that that wouldn't be used to describe iTunes now). It wasn't the iPod hardware that pushed sales, it was the marketing. Period. The fact that it wasn't a terrible product definitely helped, though.
iPhone? Ok, one legitimate revolution in most aspects, not so much hardware alone but more of a hardware AND software package that worked well together. That made it successful, but the marketing is definitely what made it mass appealing Super #1 successful and it's silly to say otherwise because sales data linked to before and after the ad campaigns explicitly link a huge upturn in sales after each successful campaign, remember some were actually not that great until they hit the sweet spot. Ditto for the Mac vs PC spots. Massive sale increases explicitly tied to advertising. Again, being able to back that up with quality hardware definitely helps.
If you can call the iPad revolutionary you can say the same about the Wii-U's gamepad. Only it actually is somewhat revolutionary in how well it handles sending video to the tablet and the distance it can transmit it given the technologies it uses to do so. And really, it could have easily captivated consumers just as well as the Wii and DS did if they had proper campaigns and software to back it up. After all, you could say the Wii-U combines two of the most successful platforms from Nintendo, the DS and Wii only "it can do so much more". Because what campaign doesn't fib or stretch the truth?
No, software is always secondary when it comes to mass consumer appeal. If it's trendy they want it. The software attachment rates to the Wii were absolutely, relatively, abysmal but because so many were sold, it didn't hurt the bottom line too much. Let's also not forget how if you keep it trendy with ad campaigns you can easily sell the successor without much fuss regardless of whether it's an worthy update. Again, look at iphones for that. Them and their half updates between true successors.