I honestly think all rooms should have microwaves - if you can find them in an average hotel chain room, you should have one in this kind of resort! We are not used to staying in such a luxurious place (really splurging here), but we always have an in-room microwave, whatever the hotel is. I hope the reason there isn't one in regular Disney resort rooms isn't a matter of profit, to make restaurants work more...
We'll have to check if we can use the one at the Mara, not sure we can without actually eating there, though. Moreover, if there is only one for the whole hotel...
(This is no criticism, just a remark!)