It's also not that Red Hat saw something wrong with CentOS Linux. To put it simply, between 2014 and 2019 Red Hat learnt that the company needed a free RHEL upstream more than they needed a free RHEL downstream.
And a lot of effort went towards making it possible to ship RHEL's upstream as a rolling release. Consider that ten years ago you had to ask specifically, months in advance, about updating a package in a RHEL minor release. In 2010, a quality engineer and I spent a few weeks working on grep just to make sure that the bugs were fixed in Fedora before RHEL 6 forked, because otherwise we'd be stuck with the bugs for years. These days I could just open a merge request on CentOS Stream and ask to update to a newer version of grep.
I may be off, but hey. As I understood it at the time, the reason wasn’t “OMG there are folks not paying us for the bits” but rather “we have this number of engineers, they can work either on CentOS Linux or on Stream” and Stream is more of a benefit to Red Hat as an upstream for RHEL.
CentOS Stream is the exact opposite of all of that, with no upside at all for this model. It will push numerous companies away from IBM RedHat entirely. Especially as it is widely seen as the start of IBM creating a bigger moat around RHEL, so there is little confidence that future clones of RHEL won't see a similar fate one way or another. And while finding a bug and not being sure who to report it to is bad, finding out that your Linux distro was buried by your maintainers half-way through the lifecycle and won't get any new updates would be disastrous.