My friend said it best. IoA is a character central park, full of characters from...
a.) Marvel Comics
b.) Dr. Seuss
c.) "Classic" strip/tv characters
d.) Jurassic Park
And their attendance is still
reportedly behind DCA. Why should Disney react to this? This is a character driven park, and isn't "stealing" guests from WDW. Disney has a clear plan right now for improvements and additions, most noticeably the reworking of "classic" attractions, additions of popular characters to the parks, and adding "solid" rides to parks (see Toy Story Mania) to keep guests in.
It's working pretty well right now, why should it change? We're not talking about psychotic over reacting Eisner leading anymore.