I’m sorry, but this is such a stupid discussion. All the great golfers lost a major they should’ve won. Arnold Palmer at age 36 (Rory is 35) lost a 7 shot lead on the final nine of this tournament at Olympic to Billy Casper, and then got waxed in a playoff the next day.
Rory isn’t doomed because he missed a few putts at crunch time to lose himself a tournament.
The bigger issue for him is that you aren’t going to give yourself infinite amounts of chances. Each one that goes by, especially the ones you are right there, that you don’t win the pressure builds up more and more. You aren’t going to get another 30 good chances in contention. Arnold Palmer never won another major after that loss, and not because he kept collapsing after that point. Getting into the position where you control the destiny of a major with a few holes left is such a rare position to be in.
Rory will win a lot more golf tournaments, but there are four majors a year and he’s getting up there in age. The chips will probably fall his way at some point soon, but the bigger threat to him not winning one is likely that he won’t ever be as close as he was again than he’d miss two putts inside four feet with three holes left again.