Adobe Inspire - what's with the text size buttons?

Even if you have seen the new Adobe Inspire site (built with Flex of course), you probably didn't notice the buttons in the upper right that allow you to increase or decrease the text size. Those buttons aren't really a new concept, lots of sites have a mechnism to increase the font size to make the site more readable for those with visual impairments. 

What's weird about the ones on the Inspire site is that, when you click the button to make the type bigger, it doesn't make all the type bigger. It only makes the body copy bigger. However, some of the headings are smaller than the body copy so it would make sense to make those headings bigger as well. I wouldn't expect that visitors to the site will understand why the headings aren't being enlarged when that button is clicked.

All in all, I like the site. Though, I am surprised that it isn't following along with the dark gray/black theme that the Adobe products seem to be using these days.