Because, you know, why not?
At the end of the day, the UFC is a business. They’re in it, like it or not, to make money. This has been proven time and time again; many fighters labeled "entertaining" have remained on the roster despite numerous losses in a row, while other slower-paced fighters have been cut after as few as one loss.
But perhaps the biggest example of the UFC being a business came when, in his third fight for the organization, Brock Lesnar was booked to fight Randy Couture for the UFC heavyweight championship.
Lesnar had lost the first fight of his UFC career, in somewhat embarrassing fashion, to Frank Mir at UFC 81. Even though he dominated the fight in the striking game and brought the fight to the ground where he was even more comfortable utilizing his wrestling and ground-and-pound, it was an eventual heel hook from the Brazilian jiu-jitsu black belt that highlighted Lesnar’s inexperience.
Though many believed he had a future in the sport, few thought he was ready to fight for the title after just one victory in the UFC over a fighter who wasn’t even in the top-10 in the division, Heath Herring.
But that’s exactly what the UFC did. After seeing how well the two fight cards involving Lesnar performed in terms of buy-rates, the decision-makers within the organization knew they could make a killing on promoting him in the main event for the heavyweight championship of the world—even if he wasn’t the top-ranked heavyweight contender at the time.
Their decision proved to be the right one, as Lesnar-Couture at UFC 91 became just the second UFC event to crack one million buys on pay-per-view. This came after Couture’s previous two headline events for the title against Gabriel Gonzaga and Tim Sylvia had not even reached 550,000 pay-per-view buys. It was very obvious a star had been born in Brock Lesnar.
Some of Lesnar’s shine seems to have worn off since his loss to Velasquez; the most recent season of The Ultimate Fighter did not get as big of a boost in ratings as some so-called experts had predicted, but Lesnar still arguably remains the company’s biggest star. Until proven otherwise, he is certainly their biggest pay-per-view draw, even over Velasquez or dos Santos, and could be given a rematch for the title just based on that reality alone.
Many people would groan at the thought of Lesnar being given a rematch without having another fight in between, but those people need to remember that the UFC is a business. Businesses are intended to make money, and Brock Lesnar makes money better than anyone else the sport has ever seen.