I had the same question. At least with the "MyPod" and "Steve Mobs," they were being quite harsh towards Steve Jobs and the hipster culture Apple has had a major role in creating. Not that that ever stopped The Simpsons from calling out targets long ago, but still. Perhaps a sign that we have too many real-life Miguel Sanchez's out there.
But with the Funtendo Zii, all they showed was people having fun playing the system and having their lives magically transformed by it. It was basically a Wii ad. Do they think Nintendo would sue them for implying that a Nintendo Wii isn't durable enough to be run through a dishwasher? I'm not about to try and find out with mine, but I'd bet it isn't. They've done far more direct parodies of Nintendo several times in the past, so what's stopping them now?
As the rest of episode went, it's definitely one of the poorer ones in recent memory.
The B-plot started awkwardly when Lisa showed up at the Retirement Castle for absolutely no reason, and finished even more awkwardly when the focus shifted to the Zii. Lisa's supposed to be responsible, so shouldn't she have bought what she went to the store for, and not the Zii, or at least both of them? It seems like the whole ordeal could have been two plots instead of just one.
Meanwhile, wouldn't Marge have been even slightly suspicious of how the family started stumbling on all the luxuries they could never afford before, according to this episode, even though The Simpsons only have money troubles when it's convenient to the plot and the rest of the time, they can afford anything at all, like expensive globetrotting vacations?
And what's the deal with Ricardo Bomba? Is he dead? If not, will he be soon? What a terrible way to introduce a new character, even if he was hackneyed to begin with.
Hey, why didn't they call this episode "Lisa Gets a Zii?"