Explain.
To be fair, DOA5 has received the biggest competitive changes compared to the previous editions. At least they tried with DOA3 but that didn't go so well yet it had some solid ideas from it, but of course that one was overshadowed. DOA5 and it's upgrades is literally the only version that receives patches and the only one being brought to tournaments while still trying to represent as well as trying it's best to remain true as a respectable fighter. DOA4 was a mess in competitive standards that barely had any updates (and had potential to do updates but they chose not to). As far as I'm aware, the competitive players enjoy DOA5 the most currently and that's the majority. The old stuff is obsolete and there are times where they have to make change and improve. They are trying to stay relevant as a series to a positive note while trying to not be overshadowed to some extent. You simply can't backtrack to the old ways and expect great change. It's an old movement that is not drawing people from all around to try the game. Hell, DOA5 has tutorials for new players to the series which the previous versions lacked. That is an incredible improvement.
As for the casual side of things, can't speak for this deeply because it is unknown if the same practices would of been the same in the past..though people have asked Itagaki on Facebook and he mentioned that he is against DLC related content because it's taking elements away from the game, but from what I'm seeing as of right now, DOA5 with Hayashi has enabled people to create fan-made costumes from a contest+DLC, absorb feedback from the fans from a casual and competitive standpoint, as well as promote the game heavily. I'm sure Mr. Wah or someone could explain it in more detail as to why.
Props for Itagaki to make such a great series as well as NG, but If there's anything Itagaki could come back for...I'd like for him to only come back for Ninja Gaiden, however not for DOA since it's a fighting game by core standards. Itagaki compared to Hayashi would probably be no different as a whole, but in terms of holding the series and staying important, Team NINJA has been doing a solid job with Yosuke without Itagaki from the looks of it.
Kodachi probably said it from an aesthetic and mood point of view.
While past DOA games had that cool early 2000s vibe all over the place and could be pinpointed well, it had a clear identity, DOA5 on the other hand is all over the place: first it monkeys American games and atmosphere, then it goes back to Japanese moe aesthetic to the point it does feel like an ecchi fighting game like Arcana Heart.
I do praise TN for the costume contests, that is the best fanservice they could possibly do, but they do it twice a year if we are lucky. And DOAX3's practices are and were garbage, won't excuse them for that.
I doubt here people will argue that Itagaki needs to be back for the gameplay aspect because in that regard DOA has never been better, but the casual POV, it's wonky and indecisive.
But if the next installment goes completely "ridiculous titty fighter" it will still be the butt of everybody's jokes. I doubt anything can change DOA's reputation now, not even going back to Itagaki's atmosphere and aesthetic.
Because even if the game was just like DOA2 which had nothing particularly jarring, nothing other popular Japanese games did not do, gaming is mostly made of male heterosexual guys who will make fun of the tits (while praising Chun Li in a bikini) because "it's just a ploy to hide bad gameplay!!11", since they are so butthurt their punches can be held.
The triangle stystem is probably at fault as much as the tits.