"Why do AJPW keep booking Misawa vs Kawada? Fuck off Baba"
"Flair vs Steambot? Again? Ugh!"
"Oh look, Lawler vs Dundee. What's this, their seventh match?"
"Freebirds vs Von Erichs is so overdone"
That's what the Okada vs Tanahashi complaining sounds like. They haven't faced each other in over 18 months, and the past two matches they've had were bonafida MOTY candidates. Let's not pretend this is some massively overdone match, and let's also not pretend that there aren't two significant reasons why they run it so much - the match quality, and more importantly the number of people they get through the doors, or buying merch, or buying PPVs. AJ is great, but look at the attendance for Back To Yokahama. He didn't draw well as a champ compared to Okada or Tana, and in fact he did worse than expected. He's not a top level draw, and as much as NJPW care about the English speaking audience (A tad, maybe a mild amount), they care far more about trying to sell out the Tokyo Dome and got PPV buys within Japan. They only have three proven main event draws right now, why would they decide to take one of them out of the main event for what would be a worse match to appease the at most few hundred westerners who's decision on purchasing the PPV/NJPW World rests on AJ being in the main event?
As far as "one of" the main events, he's in a top 3 match vs a main eventer. It's not like he's curtain jerking when of the guys above him three are NJPW's three top guys, and the other is a guy who has been the top drawing jr heavyweight in the country, who is being pushed up to main eventing as a heavyweight in a re-match of one of the best matches of last year.