That doesn't make his ideas or theories or gameplay additions or updates any better than anything the PMBR is doing. That's not to say that what he has done is good or bad work, but ultimately the released result (and the post-release fixed results) is ultimately what people judge a game by, not "how many hours you works".
Also, working less hours (say 60 hours a week tops) would be beneficial to Sakurai for development, as it would make him fresher. Warren Buffet is one of the richest men in the world, and he became rich despite working very minimal hours. But man, when he worked, he worked, and he got work done, and made billions off it.
That's my point, Sakurai is putting EFFORT in this game, effort requires time, but he's really focusing on making something that fixes the flaws of past and can provide the ultimate experience, at least according to him. He says he tries to look at even the smallest details of the game and supervise these areas to make sure it leaves an impression as the best Smash. While I respect all unbiased opinions (such as your own, when it comes to P:M), I myself don't really see any blatant problems with the new Smash so far. He doesn't need to get swapped by modders and I also think Nintendo makes great home console games (just look at 3D World) on their own, they just, like you said, suck at advertising. I understand that Sakurai's posts may upset you and I acknowledge that he isn't contributing to the hype factor as well as he could be, but you have to remember that deep down, the very fact that he even posts updates on a daily basis at all is pretty surprising. Heck, sometimes we get something new, even. I'm not saying you shouldn't be disappointed, but condemning the creator of what seems to be one of your (and my) favorite franchises over something he could choose not to do in the first place is ridiculous, to be frank. Yes, Sakurai is missing many opportunities with these joke pics, but there have been at least 30 pics so far that have revealed something new. That's more than what most franchises can say. Look at Kingdom Hearts 3. I'm hyped as ever for that most-likely-to-be incredible game, but the public has practically no knowledge of what it will actually hold in store. Call me a "Sakurai fanboy" or "fantard" if you want, but at the end of the day, I just see myself as another fan of a series of video games I like to play. If that means being optimistic and looking past the lesser quality gameplay of Brawl to a brighter future, then that's just what it's going to be. I personally think he knows what he's doing, he has flaws, but he's the same guy who made Melee, the same guy who added the wonderful side contents, updates and extras (Music, for example) in Brawl, and same guy who started this all with Smash 64.