There's more at work on the pro-ESC side than meets the eye...
Too many in the public believe that stem cell research will hold all the answers to man's ills. Grant hungry scientists are making promises that stem cells likely won't be able to deliver.
You see, we don't know how stems cell WORK yet, let alone how to make them into these wondrous silver bullets we have been promised. We are years away from knowing whether or not we can even use them without mutation dangers.
Until then, the scientists will yell "We need more lines! (and funding)" ad nauseum.