Most support, even enterprise support, really is crap. Red Hat support is (usually) far above the rest. When I worked for Red Hat, I regularly interfaced with support staff at partner companies, and they were usually a long way below anyone who was out of training. (Before anyone chimes in with their horror story, yes, some people manage to make it through training and bungle a lot of stuff before getting fired/reassigned; some tickets get triaged by a n00b who doesn't know what they're doing; and sometimes even the experts mess up. That's when you should be requesting escalation, no matter who you're talking to.)
That said, a lot of people don't need the kind of support that Red Hat provides. Red Hat's business model focuses far more on the large enterprise than SMBs. When SMBs use RHEL, it's often through a VAR who's also helping them with whatever they're deploying on RHEL. Red Hat gets a smaller cut, for less work. CentOS is just fine for many people, at least until they grow to the point where they need a support subscription with SLAs. Red Hat gets a ton of business from people who use CentOS until they grow enough to justify fixed-price subscriptions with SLAs. The sales team doesn't lose any sleep over it. Most people who choose CentOS over Red Hat are either completely rational in that they don't need that kind of service, or they customize too much of the distribution for Red Hat support to be economical, or they're just really cheap and would inundate support with trivial questions rather than shell out to send their admin to a (very good) training course.
If you think CentOS is better for you than RHEL, odds are you're right. You don't need to guilt trip yourself about being a freeloader. Report bugs, frequent mailing lists and chat rooms, and do whatever else helps the CentOS community, because it's ultimately good for Red Hat and the community at large. Red Hat is running a profitable business, and doesn't need charity.