Unification my a*s, these fighters fight for money and fame. The exposure and money sticking around and fighting ANY of the guys featured on the superfly tournament (not just a champion...) there's so many BIG names and good fighters to choose from. He didn't want to fight them if he's moving up.
You either fight for a world title, or a big name to make your resume look better and get more exposure. These fighters don't care who is more skilled than who, they want to fight the biggest fights possible. Those guys in the superfly tournament, those top 5 guys are all bigger names then Tete at 118.
That's like Sadam Ali choosing to fight Jeff Horn at 147 instead of Miguel Cotto at 154. Yeah you get a belt, but you won't get the same money nor exposure. Plus, both are winnable fights.
Let me put it like this: Inoue has yet to reach his physical prime. He's 24 years old, and is a constantly growing fighter. He became a super flyweight champion at the age of 21, having to waste a year fighting only once due to a hand injury. He's growing out of the division after having been there for three years. Inoue needs to move on from the division.
From what I have seen, Inoue has negotiated with Gonzalez, Cuadras, McJoe Arroyo, Ancajas, Yafai, Concepcion, Kono, and Estrada. That's nearly every big name in the division. Rungvisai was owed a mandatory shot for the WBC belt since 2015, so he was biding his time. All of these negotiations with the exception of Kono fell through because of different priorities (Arroyo, Cuadras, Gonzalez) or because they outright don't want to fight him (Ancajas, Yafai, Concepcion). All of these offers were made when most of them were still champions at the time. Instead, Inoue had to go for mandatories and voluntaries. And even the mandatories didn't want to fight with Inoue! Tso and Conlan wanted nothing to do with Inoue, and Estrada wanted to fight Gonzalez, so he went the WBC route. Once again, I haven't seen any reports where Inoue turned down an offer against a big name. If you could find one, please let me know. I want proper sources that say Inoue is declining offers to fight big names. Quite frankly, it seems like the other way around. Inoue wants to fight the big names, but they keep avoiding him. It's been like that for the 2 years Inoue has been active at the division (I don't count 2015 because of the injury). I only cite the unification deal because that's what Inoue wanted for the end of 2017 or the SuperFly2 card. For the entire time Inoue has been in the division, only Gonzalez and Kono made an effort to fight Inoue. I remember when Gonzalez vs Inoue was seen as the superfight of the lower weight divisions. They both so badly wanted to fight each other. Alas, Gonzalez spent too much time trying to build his name up, and ended up losing to Sor Rungvisai twice. Those are the facts of the matter.
Do fighters want big names, regardless of the belt? Sure, of course. They are called prizefighters for a reason. Inoue has been chasing big names since 2016. Nobody would accept Inoue's offers. Inoue was running out of time to make a mark on the division because of weight issues, so he wanted a unification fight before he moved up. Gonzalez was planned, but he lost. Ancajas and Yafai ducked Inoue. Rungvisai is busy with Estrada. So Inoue moved up. Inoue has called out literally every big name in the bantamweight division, and is willing to travel to the U.K. to fight McDonnell, Burnett, and Tete.
The lower weight divisions aren't like the higher ones. Because these guys are smaller fighters, even a 3 lb. difference in weight is a big difference. That's why Gonzalez struggled so much at super flyweight. He is a smaller guy who started at the lowest weight available and is fighting against guys who rehydrate to lightweights. Inoue can't switch between super flyweight and bantamweight at will. Inoue moved up for a reason, and it's because of weight and issues getting a fight while Inoue could still make the weight. Inoue isn't ducking anybody.