The American Healthcare Act was a poison pill.
If it passed, the GOP would lose a good number of seats in the house and probably lose their majority in the Senate. They were caught between a rock and a hard place.
The solution was incredibly elegant and a masterpiece of politics. They keep enough in the bill to let the Tea Party crew scream bloody murder, which lets the rest of the GOP off the hook. No vote, no foul.
The best part is where Trump declares it a dead issue. It was so dead, no one even bothered to say, "Hey, we've got plenty of time. We don't have to do it all in a week. We start over Monday morning and go at it again."