Reasons might sound silly or lame to some, but it depends on your usage. If any of the below does not hurt you, please go ahead and buy it. It is the best one out there.
No SD slot
If this is billed as entertainment device on the go. Then that memory of 8GB/16GB is not enough. So to offset that a SD card slot with max capacity of 32 GB would have been great. In fact the sd card slot is a standard in Android tablets.
The bottom of the device, though gives a good feel could wear out pretty soon.
Really!! Yeah to some extent size matters. As Steve Jobs pointed out 7” is just around 45% the size of the 10” tablet. Though it is a good reading device, consumption of movies would not be ideal. Even games like Angry birds and others would be way better when played with a 10” tablet.
7” inches is more of a mobile tablet, if you need one. It is more of a larger mobile, than a tablet. Even Google seems to agree to that fact, since they have used a mobile skin for the tablet rather than a tablet skin.