Fact: Most headlining fights are non title fights.
Fact: The frequency of injuries during training is high, often resulting in late replacements.
The fairness of a fight with one fighter who has a full training camp for a 5-round fight vs. a late replacement who has been training for a 3-round fight is highly questionable. In fact I call it downright unfair.
Case in point? Masvidal vs. Henderson. Masvidal pretty much stated the obvious in the post fight interview; training for 3-rounds doesn't cut it for a 5-round fight. Sure there is always a chance of an early stoppage, but not so much with the elite fighters. If you're the guy who's been training for the longer fight, then of course dragging it out early so you get later into the fight is a pretty obviously strategy.
Fact: Masvidal vs. Henderson was not a fair fight.
I like to see fair fights. The UFC is just creating situations where main events are not fair fights. They are increasing the chances of having an unfair main event. The late replacement fighter for a 5-round fight is a lamb being led to the slaughter. These guys are tough and a headliner spot is desirable but it doesn't make it a wise choice.
From a sporting perspective, a 3-round non title fight is the most logical. Obviously from a business perspective a 5-round main event is more logical. The fighters have no say, but does this make it right?
From a fighter longevity perspective, non title fights that are 5-rounds will increase injuries and recovery times. Most every non title headliner is not a contender fight so a longer fight ultimate proves nothing. Getting a call and agreeing to be the late replacement for a 5-round fight wins you favor how? If Masvidal declined, what happens to him?
It's a game of odds. Do away with 5-rounders, add another fight instead to the card and then at least keep the competitive nature of the main event should the need for a late replacement come about. It hasn't been the biggest issue of late, but why increase the odds of having a mismatch or a less than fair main event.
Give me some logic why 5-rounds are better for a main event, from a fans perspective. I'm all ears.