Nobody is claiming that McCain should go without credit. It’s the giving of sole credit that’s a bit bothersome. Especially since another Republican Senator, Lisa Murkowski, voted against the bill even though she had been threatened by Trump if she did what she did (McCain wasn’t subjected to bullying tactics).
And it wasn’t that McCain voted yes on the motion to proceed that got people’s ire up. It was his vote after that — on the first repeal and replace bill that same day — where he voted yes.
I believe the vast majority of Americans are sorry that McCain received a horrible cancer diagnosis. Nobody should have to go through that. But that doesn’t make him immune from criticism when he votes to take away health insurance from millions of others, as he did when he voted for the repeal and replace bill. Fortunately, he wound up doing the right thing on this last bill.