Optics.
Perhaps it is the plan to make DJT speaker of the house. The optics would not be as good if 45 opposed McCarthy because he wanted to be speaker of the house.
Now Trump can get a nomination without that fight against McCarthy.
After all, McCarthy is the first failed speaker vote in 100 years. We all know Trump's world consists of Longshots.
People say that Trump is bad at picking people but if you don't see the pattern it's easy to be confused.. Swamp creatures rely on swamp support of a manicured persona consisting of carefully crafted lies and glossing over shady deals plus lots of money. For some reason when they get into Trump's orbit they can no longer hide who they are. I don't know how he does it, but it happens so regularly it has to be deliberate.
Picking people who fail is not the same thing as picking people to fail.