Yeah, well he didn't say outright that it was a bad idea, more that it simply didn't worked out as hoped. But I think we all know, that he knows, that he fucked up. That simple. I mean he was stating the obvious anyway, you would have to be close to brain damaged to actually think that Fallout 4s dialog and gameplay is awesome for an RPG. Like I said a couple of times, you can enjoy the game, but you really can't say that it is an great RPG.
You know, I honestly wouldn't be surprised if someone who's higher on the food chain than Todd actually gave him some very hard time, because of the metacritic and other mediocre/bad reviews by players. Unreasonable? Well, they made a whole deal based on metacritic with Obsidian and New Vegas, remember? Who knows how much of a role it plays in their development.
But hey, that's just a guess.