Yes, the rate of market penetration, by the iPad, because of the history of the iPhone, and the app store success, really drove a lot of momentum that will be hard for competition to beat. I have friends, as I am sure others do, who have no idea what might compete with their iPad or iPhone, because for them, it is a toaster. It does what they need, and it's not a problem for them to just use it.
The tech crowd are more easy to sway and bring to bare as a marketing force. This is why the other tablets have not been getting traction. The non-tech market is satisfied with iOS devices. The tech crowd is being hyper critical of the Android devices, because they want to be able to tell their friends to go buy one. The problem is that the software and hardware shortcomings of the tablets have kept the marketing from the tech consumer side from happening, and they are really the only ones that can understand the Android tablet commercials/advertising that is coming toward consumers at this point.
Watch the iPad commercial. It's about solutions, the average "Joe" gets that. Watch the Android commercials, they're about "features" or "better than" or "wow factor". That is hard for "Joe" consumer to understand. Now, because both iPad and Android have similar capabilities and features, just doing a "solutions" advertisement is hard to do, without making things look like "we are the same as them".
I really think that marketing is the big thing that keeps Android tablets on the shelves the most, but the technical bugs are not to be lightly considered either.