USA Today has that answer.
Republicans to Democrats: Shut the Hell Up
Democracy in Action!!!
"The changes were offered in an attempt to attract support from the hard-line conservative House Freedom Caucus, a group of about 40 Republicans who have so far mostly opposed the repeal-and-replace bill because it retained too much of the structure of the Affordable Care Act. It was not clear Friday whether the changes were sufficient to appease that group. There will be no amendments allowed on the floor." (emphasis added)