Protecting the title sponsor is good for the whole series. It adds value to the company who is spending big bucks to promote your sport. In return, they should be allowed maximum opportunity to promote their interests. It is not unique to NHRA, AT+T was not allowed to renew their title sponsorship with Jeff Burton/RCR because it directly conflicted with NASCAR's Nextel/Sprint deal. Opening up the sponsorships might be good for a few teams who MIGHT pick up energy drink sponsorships (Monster certainly wasn't impressed with NHRA) but you risk upsetting the whole applecart. Much easier to get a few teams to shake other trees for sponsor dollars than it is to get a partner to foot the bill for the whole series. I am all for the teams getting their hands on as much sponsor dough as they can, just not at the potential risk of long-term financial health of the series. Coke/Full Throttle know there are other energy drinks out there, but for 23 events a year they have a captive audience and TV to add/convert customers. That is the real reason they are here. The message definitely gets muddled if there are 3 or 4 energy drinks on the grounds trying to accomplish the same thing.
And like everything else, NHRA will be in the wrong no matter what. If there was no sponsor protection, and a title sponsor left because they felt they had diminished value because of all their competitors in the same venue, people would be on here complaining about why NHRA would let that happen.
Lastly, Jim Jannard had a good post here on the Mater a couple of years ago about this very issue when Spy sunglasses tried to setup a trailer on NHRA's midway and Oakley called foul. He has spent and forgotten more about these topics than any of us ever will know.
EDIT: Red Bull is leaving NASCAR for the same reason Monster left NHRA, they aren't reaching their target demographic and/or expanding their customer base. It makes it easier for Red Bull to leave because the NASCAR program has not been succesful at all compared to ther endeavors (F1, action sports).
