So basically, if the GOP cannot even make small changes, Obamacare will become the de facto consensus on how healthcare should be done, and as problems become more obvious, the GOP will own those problems.
Even small changes would have left the option of fixing more. Doing nothing will not.
The proposed changes are anything but "small". Each bends the ACA in a conservative direction. But you are correct, ANY changes, big or small, must, as a practical matter, be agreed to by all Republicans (only two defections are permitted). In the absence of solidarity, not even small changes can be made, because the Dems are unanimous in opposing all changes.
What the GOP in Congress has to have drilled into their skulls is that when the Dems are unanimous in opposition, the GOP must be unanimous in support. That's why Barnes says, correctly, that EACH and EVERY GOP member needs to be a team player - to go along with Party leadership notwithstanding dissatisfaction over details.