Hello @bob1962 and welcome!
I’m far from being an expert.
However, when a software or some kernel component crashes, the system tries to create a crash dump/report that can be useful to attach (or automatically send) to a bug report.
In this case,
kernel has been tainted means that there are proprietary/third party modules that prevent this report to be useful, from the point of view of a developer. The kernel crashed but who knows, due to these additional modules, where the problem is? The problem would have happened anyway, or the problem is with these third party stuff? Since this third party stuff is proprietary (no access to the source code), or in any case hasn’t be provided by the kernel developers/maintainers, why should I (developer) waste my time investigating on a problem that is very likely impossible to diagnose?
Something crashed and the eventual crash report is unuseful.
(Software crashes, it is not a mystery; if the same problem happens to many times, then there is a problem).