Smashboy... with all due respect, I don't think you understand how game porting from one console to another fully works. by "engines" I assume you are referring to the "graphical engine" yes? They won't look the same on all consoles just because "it is the same game". Please do not caps-lock your comments and be rude with people, first of all. It is fine to have an opinion and state your view, but can we please be courteous?
When a game is developed for multiple platforms - or even made for a newer one later on - the developers have to completely rework how the controls will operate as well as redo a very large portion of the graphics they had already placed out. this is why games come out way later for one console than it does for another. And even why some games get cancelled. I am trying to think of it, and if anyone can, by all means feel free to add it in, but there was a game a couple years back that was supposed to come out for both the PS3 and 360 on the same day but ended up being only on the Xbox 360 console because the developers couldn't figure out how to move the graphics over to the PS3 at the time.
Besides, if what you said was true, you would be saying that Call of Duty world at War - also made by Treyarch - looks the same on PS3, 360, and Wii. If you have ever seen it on the wii you would know that it "is not the same because it is the same game". Each console has different UI and Graphics cards and color chips so none of them look exactly the same. They also have to take into account what the multiplayer will play like running those graphics. the 360 has the best bandwidth - which is why you pay for gold to play online - and the Wii and Wii U have the worst. Having the same graphics or even similar graphics as the 360 and PS3 would make the multiplayer a laggy mess or constantly disconnect.
I can show you official schematics of each console if you like. I just need ask my boss for them. Just because I work for a review site that covers only Xbox 360 games doesn't mean we only like the 360. We happen to have a Club on PS Home and obviously I love my Nintendo handhelds. I even WANT a Wii U when and if a few games come to the US. So yes, we follow everything happening with all consoles very closely. Stonewoot has worked with us and is one of the biggest assets to our multiplayer features testing as although he is not listed as an employee, he gives me a lot of his insight and is the one to play test most games with me. Much like my boss who worked for Yahoo, AOL, and Microsoft and designs the site by hand, Stonewoot has a large background in PC and software / hardware design for them. He actually knows what he is talking about despite being a REALLY bad speller lol He just has problems conveying his thoughts properly, much as you or I have problems of our own.
You are correct in that Nintendo doesn't force cartoony graphics upon the devs, but what Stone meant was that the Wii U, because of how it outputs video, made it look less realistic than the other consoles because it is made more for first party games and more for children. Thus brighter colors. Although, Nintendo has mentioned they plan to get into the more adult-oriented games with this console much as 360 and PS3 have, and is trying to prove it with Bayonetta 2. But the "cartoon" comment, I think, is best put like this... I doubt Mario would shine on a 360 or PS3 as it does on a Nintendo console. The graphics are made for him on a Wii or Wii U.
And yes, you are absolutely correct in that it needs time for developers to tinker with it more, but his point of "sharp" edges is clearly seen in Batman Arkham City. His shoulders, for example, look to put someone's eyes out when compared to the other consoles. Does that mean the game is bad? No. Does it mean the Wii U is inferior? As of the moment, graphically, yes. But like you said, give it time.
Stone was giving his "thesis" as you so put it, on the current games he played and relating it. He wasn't stating anything about the future of it. As the question in the topic states "why haven't you bought one yet?" Not "why are you never buying one?"
You've typed way to much for me to want to reply,talk about text overload. The othe poster brought up engine,is it not a fact that all versions of blops 2 run on the same engines? The only time they'ed have to be optimize,is it had to go to the classic Wii becuase its weaker.
I'd rebuttal more but to much text to be interested. I type in ANY TONE I WANT and next time,dont be affraid to quote me so I could see it.
And no, they do not all run on the same graphic engine... they run on the same GAME engine. I think that is where you are confused. Like for
example, Wolfenstien for the 360, Call of Duty: WaW, and CoD: Black Ops 1 &2 all run on the same engine. Their controls play similar and the
basic build is the same but the graphics are different in each game and on each console. Even the controls need to be changed and tweaked in each version.
I seriously suggest looking into how different games are made for multiple consoles. You may find it very interesting.

Before my boss began teaching me I didn't realize just how much work goes into moving a game from one console to another and I always wondered why some came out sooner for a particular console and others got pushed back.
The game engine is what we were talking about,thats why I said if they look cartoony on WiiU,they'll look cartoony on everything else.
The game engine has nothing to do with the graphic engine, Smash; those are two entirely separate things. you can go and download a copy of Doom 1 for PC and I can do the same. We can get them from the same source too... then I will go to the open source Doom website and upgrade all the graphics to fully rendered CG ones and over-write the entire graphical engine on my copy. Both our copies will run on the same game engine and play the same but look nothing alike.
No one brought up the game engine until you first incorrectly used it as an example. You were the only one talking about a game engine and it didn't even make sense where it was mentioned. Game engines have almost nothing to do with graphics if they have anything to do with them at all.
And this is my final post on this matter. I grow tired of trying to converse with a wall.
Read my 2ndresonse,there were edits im sure you missed. And your talking about a pc game,theyll look different becuz our machines probably arn't the same in specs,which leads to what I was talking about with DOWNSCALING, Console specs stay the same. Your crazy.