That's the problem.
It may be easy for you to say "why" (which you have not) as you attached to particular past accomplishments as Gov. of the State of Mass.
Romney is not politically free to say "why". The problem is, he was planning on the SCOTUS to declare a NATIONAL version of RomneyCare with an individual mandate to be unconstitutional .
Now that it is considered constitutional by the highest court of the land (a curve ball to Romney) he's trying to figure out how to approach this without putting himself in a bad situation with his own RomneyCare.
That's why Romney cannot get past "it needs to be repealed" to say WHY it needs to be repealed.
Romney is stuck between a rock and a hard place.
Bingo!
His advisers were more interested in defending Romney/Romneycare than they were in attacking Obama.
He’s fighting with one hand tied behind his back.
Now that it is considered constitutional by the highest court of the land (a curve ball to Romney) he's trying to figure out how to approach this without putting himself in a bad situation with his own RomneyCare.
That's why Romney cannot get past "it needs to be repealed" to say WHY it needs to be repealed.
Romney is stuck between a rock and a hard place.