While Coverity does incorporate Findbugs results, it also has its own analyzer that does much more interprocedural analysis and tends to be tuned better for fewer false positives and more accurate error messages. Historically at least, part of the reason for incorporating Findbugs was to make it easier to directly compare what Findbugs found with what Coverity's analyzer found. Because every customer wanted to know that.
I have no idea of current figures but historically Java was not a big business for Coverity. Other vendors had much more Java business (and incidentally also incorporated Findbugs results).
Finally, as you can see from the message the Findbugs leadership does not seem unified and easy to collaborate with.
So forgive me but I find your comment and its tone a bit unfair.