If Sony had established franchises that they could milk (Ratchet & Clank), then I'm sure they would (GoW). Sony has no choice but to introduce new IP's because they don't have a stable of long standing guaranteed sellers like Nintendo. MS would do the same exact thing if they could (Halo), but they have the same problem as Sony.
WiiFit & WiiSports were both HUGE gambles (also read as RISK), it's just that they both paid off HUGE and Nintendo should be proud of that. Just because they (DS, Wii, Wii____ ) are the huge successes that they are today does not mean that they were safe bets and it was not known that they would be "embraced" when they were being developed, since nothing like it has ever really existed in the console space before.
And if we took a look at the history of Sega, we would all know that releasing peripheral after peripheral was a big no no and risk not worth repeating, but Nintendo did it anyway.
As far as games like LBP go, I don't think anybody bashes the game because it's from Sony and it was hyped to all hell, I think they bash it because it wasn't very fun or good. It was pretty, and functioned as demonstrated, but it just wasn't a fun game to play. I'm pretty sure no one here knocks a good game just because it's on a different system, otherwise Uncharted 2 wouldn't be getting the praise that it is.
And Nintendo did take a risk with a new IP, WiiMusic ring a bell? I remember everyone ragging on that game, even though some liked it, a majority of the internet was like WTF Nintendo, WTF is this ****!? SO once again, I'm not really following you here.