Because that's the only platform that competes with Apple (other platforms with bigger market shares are targeting different segments of the market).

On a side note, take a look at this PARTNER AND INDUSTRY FEEDBACK:

http://www.adobe.com/aboutadobe/pres...uoteSheet.html

You've got quotes from nigh everybody, HTC, Google, Sammy, Moto, RIM, MS, Dell, Qualcomm, TI, Intel, NVidia, basically everybody except Apple (as expected). But also missing is Nokia. Don't tell me Adobe 'forgot' to ask Nokia for a statement of support ?