I was an ASIC designer my entire career. My poker buddies at AMD are designing the graphics engine that is going into the PS4. I know more about this level of technology than I care to admit.
I don't think you have the basic understanding of how much power is needed to run a hard core gaming system and how hard that is going to be to fit into a tablet format and not destroy battery life. You don't make those types of power savings leaps in the significantly smaller packages needed for a tablet over the span of one or two years. Technology moves fast, but not that fast.
If you are really under the impression that the design cycle of the Ipad's is less than 2 years old, I have to also say you don't understand the basic concept of a design cycle. The Ipad 1 design cycle likely started much before you think. Certainly significantly more than just two years ago.
Maybe you could better understand that if the Ipad was launched in 2006, it would not be anywhere near as powerful as it was being launched in 2010. The technology simply was not available yet whether they wanted to design it in or not to support their size and power requirements. By waiting out the years, they were able to take advantage of the process improvements that have occurred in the ASIC industry which typically take a few years to get to a new level to support a smaller size and better support for power.
The consoles have relatively little worry about room or power, but that is the main concern for the tablets. Making the technological leap from the size of chips and power the consoles are using to what the tablets will need for an equivalent can not covered in a 1-2 year time period. It has NOTHING to do with Apple concentrating on it as they do not control the ASIC process industry.
A better example is the PS Vita. The internals of the PS Vita, designed specifically for gaming, now are roughly equivalent to the PS3. Again, that is a 6 year gap before they were able to get the same level of technology in a small package (obviously smaller than a tablet, but also significantly more focused on a gaming than a tablet ever will be). And the battery life of the Vita (at roughly 3 hours) would be unacceptable to the tablet market which now is going to expect 9-10 hours.