We already know and have known for years what disdain the left has for mothers and motherhood, so in a way this really is a meaningless controversy.
I think the attempt here is to create sympathy for Romney. Remember that Ann Romney is a liberal, she is pro-choice, her friends are all Democrats. This is the company she keeps.
Alternative: The Media and Romney are co-operating in the Romney/LSM hustle of GOP'ers past the remaining primaries to their "now is the main event joined" fraudmeme. (With over 1000 GOP delegates still unallocated and Romney still stoppable.)
I think they both know that it might not be over, and that it would be more convenient for their purposes if it were over, so the 'Rats start up this "Hey, how about that lousy Ann Romney?" meme to hook the conservatives into defending Ann and blasting easy, cheap targets like Maher .... and walking right past the ball, which is all the unfinished business in the primaries.
As for Maher ..... he probably couldn't prove he *had* a mother.