I think more of them are CONCENTRATING on it's cost, rather than it's size, just like the original iPod mini. No retina screen, and using internal components from two generations ago?
I think they set the bar as low as possible on this version, so it will be easier to come back in six months to a year and announce what a vast, drastic improvement the new one is during the keynote.
There is no doubt that cost is definitely a factor here, but anyone walking into Apple is going to be ready to spend some serious cash (compared with the competition). What I mean here is that cost is a factor to consider, but not the deciding, or maybe even a big factor at all.
I'm sure a lot of people who bought the iPad Mini can also afford an iPad (fourth gen). I think the savings is just an extra reason to buy the mini, but not the deciding factor in whether people would ultimately get the mini over the iPad.
It is generally agreed upon (from what I've read so far), that the iPad mini form factor just suits a lot of the existing users better given that their existing set up already has highly portable devices. They are simply seeking even more portability without compromising too much usability, so the iPad mini is naturally the "better' choice.
Some people who feel that the Retina Display is a must and already have a large power-oriented, rather than portability-oriented setup, would rather have the full sized iPad, making that iPad "better".
With this line of thought, you can almost classify the iPad (4th gen) as the "Pro" device and the iPad Mini as the "Air" device. "Better", then, is simply based on perspective and use rather than the overall machine.