The people making this decision are not 5 year olds. They're not "letting everyone get used to the idea." That may be a nice side benefit of their decision process but the driver is crew safety and data on thruster performance. If they find a rationale for the failures that makes them confident in Starliner they'll use it. That's what the delay is about, not "letting everyone get used to the idea."
I would like to believe you, unfortunately previous events show that decisions are not driven primarily by crew safety and data on thruster performance. Politics plays heavily in most decisions.
(e.g., the Shuttle was sold to Congress as a multipurpose vehicle that could support military, scientific, and commercial missions. However, the need to gain political support led to compromises in its design, particularly the decision to make it a reusable vehicle with an orbiter that could carry large payloads, which led to safety issues. The political drive for cost-effectiveness also led to the program being underfunded, contributing to the Challenger disaster in 1986.
The 'Journey to Mars' program was designed to sustain NASA's long-term goals but lacked a clear timeline, partly due to political hesitance to commit to a specific date or strategy that might not align with subsequent administrations' priorities. The program was influenced by political leaders' desires to show progress in space exploration while avoiding the high costs and risks associated with a definitive Mars mission plan.)
In PR terms they are managing the Overton window. As a strategy it is sometimes called gradualism or incrementalism.
Five-year-olds do not use this technique, they do what they want when they want to with no regard for their public image, which is what you are stating NASA will do.
I don't see why NASA would need to manage any "Overton window." NASA loses very little if they decide to send the astronauts back on SpaceX. At worst, and this is very possible, Boeing uses this as an excuse to just ax Starliner, and NASA would be left without a secondary crew vehicle, but they won't lose funding, and their image would probably only go up since they would have made a choice in the interest of safety.
Boeing, on the other hand, stands to suffer a lot of PR and financial damage should NASA make that decision. They have an interest in managing this window. They've been lobbying NASA and tweeted something about how confident they are in Starliner, but they appear to really be on the backfoot.
The whole point is that NASA isn't "letting people get used to the idea." It's really no skin off NASA's back if they send them home on Starliner.
