The weird thing is, that open source vendors - for all their talk - are almost as bad as the closed source ones. Atleast there's a build from source solution, though.
All vendors suck to different degrees. Nothing ever works perfectly. Open source gives you the ability to do something if the suckiness affects you, though. With closed source, you're stuck until the vendor gets around to your bug. With larger vendors, this may take forever.
While this is a pretty serious problem in a pretty darned popular and important package (and I'm a Perl developer with well over half of our customers running RHEL or CentOS 5--so I'm a little more than distressed by it, since most of our customers may be seeing our software run slower than it should be), it is not apparent to me that there is a great solution to this problem--upstream has fixed it in the 5.9 and 5.10 branches, but not in 5.8. So, the only real solution is a binary incompatible change. RHEL guarantees no changes that effect binary compatibility across the lifecycle of a RHEL release (unless absolutely necessary for security or stability--and even then, I've seen them opt not to change something, because the stability issue only effected a small number of users and the binary incompatibility would have effected everyone).
It's a hard problem to solve--the implication that Red Hat are ignoring it isn't really fair.
That said, some of the folks managing tickets in the RH bug tracker are assholes. I've had very few positive experiences when filing bugs about RHEL (they did finally deal with my two tickets about how much up2date sucked, by deprecating up2date and replacing it with something awesome, so I'm feeling pretty good).