This is exactly the kind of vague, hand-wavy answer that I was hoping wouldn't be the response. It doesn't really show any understanding of the problem. The issue with the "profit motive" as an explanation is that it's so vague it can be used to argue both sides at the same time. The profit motive helps them pay for the best-and-brightest. It also biases them to hiring the least experienced at a cut rate. It incentivizes them to provide the best product. It also incentivizes them to cut corners to save money. It explains why SpaceX has been able to move fast; it also explains why moving fast caused such problems with Boeing's Starliner. So the "profit motive" doesn't really explain anything. Besides, the vast majority of NASA work is done by for-profit contractors and has been since the Apollo era. There's nothing new about it in spaceflight.
I'll try to illustrate a more nuanced perspective. It's no secret that NASA levies a lot of tough requirements. For example, contractors must have a robust pressure systems program. This includes managing/certifying systems all the way down do small air compressors in a vehicle maintenance shop. Same goes for software quality and a million other aspects of spaceflight. Contractors hate these types of requirements because they're expensive. Many within NASA hate them, too. Certainly some of this is bureaucratic overreach, but a lot of it is also good, sound engineering practice. There are mechanisms to waive these requirements, but few people want to openly do so for a variety of reasons. I could go deeper into the why but it's a bit of a digression.
So what does this have to do with SpaceX? CCP, IMO, is a clever work-around to avoid accountability to these requirements. NASA, rather than buying a product, is buying a service. So even though NASA expects them to meet those same requirements, there's very little oversight to force them to do so. Some people have raised flags about these issues but are essentially told to stand down because they don't want to tell the contractors how to provide the service. It also gives NASA a smokescreen to get what they want (faster, cheaper production) while avoiding accountability when things go wrong (they can always point to the requirements they claimed they wanted, but didn't provide the oversight to ensure). NASA knows those requirements rapidly increase costs and on one hand they don't want them, but on the other they want plausible deniability if something goes wrong. Minimizing requirements can streamline the process. The fact that they manage way less requirements is why SpaceX can have a single 23 year-old managing a program that takes a team at NASA. In other respects, it turns a blind eye to the very requirements that manage risk.
E.g., Falcon 9 had supplier quality issues that lost a rocket [1]. Most who work with flight hardware would be surprised to learn SpaceX wasn't applying industry-standard supplier quality checks on critical flight material. Once a mishap happens, NASA gets to swoop in and investigate. And the result is SpaceX now has multiple reliability layers to mitigate that risk. It's not that it was some unknown risk, it's just that they weren't managing it properly. To the uninitiated it looks like they were running a tight, streamlined ship but in practice it was being played a little too fast and loose. Boeing did the same with Starliner but had a bad roll of the dice. The real question is how many times can this happen before SpaceX starts to look like their bloated competitors? NASA could do the same by just peeling back requirements and upping the risk.
Starliner also had it's own host of quality issues as part of CCP. People at NASA were concerned, but their hands were essentially tied until there was a smoking gun in the form of a botched demo that risked crashing into ISS. Again, the "profit motive" at work can sometimes mean more risk than intended.
As a different example of risk, SpaceX can create an assembly line of manufacturing to reduce financial risk. NASA can't because they they are also forced to reduce political risk by spreading programs all around the country. It's not that NASA is so incompetent that they can't figure it out, it's that they are managing a different set of risks. NASA manages the risk that ensures funding for SpaceX while SpaceX manages the financial risk of manufacturing. It's a symbiotic relationship, but one that can be misconstrued by the ignorant as some public/private dichotomy.
Yet another example of risk: Lots of people want to point to SpaceX rapid iteration as a strong point. It is, but people also need to understand that rapid iteration is also at odds with reliability. SpaceX may just quickly change a design (see their COPV mishap) but it's up to NASA to figure out the true failure mechanisms on their own dime. This rapid iteration is also why Tesla's quality measures are usually quite bad. They can't stabilize a design or supply chain long enough to generate high quality.
Suffice to say, there's lots of good and bad tradeoffs of the public/private dynamic, but just saying "it's the profit motive" explains none of them.
[1] https://parabolicarc.com/2016/06/28/nasa-investigation-space...