When you give money to redhat, you buy insurance that if you encounter a problem, they will support you. It is expencive, but there is clearly a lot of work involved in producing new release. IMHO redhat deserves its money. When you give money to Oracle, you are financing lawyers who try to find the best way to make you pay more without improving the software.
"IMHO redhat deserves its money". I agree. But the vast majority of people employ CentOS which is redhats derivative. Oracle engineers work hard on java and deserve their money but the vast majority of people employ OpenJDK which is OracleJDKs derivative.
CentOS is more of a repackaging of Redhat -- the binary files are almost exactly the same there so the comparison isn't quite valid.