Wii U

Is the Wii U sales slump somewhat overstated?
Yes and no. The Wii U could be doing a lot better then it currently is but like all things Nintendo related, this is way blown out of proportion.

Are people just quick to jump on Nintendo's bash bandwagon?
For the most part yes. Vita for instance didn't receive the overwhelming amount of hate and bias the Wii U received before it launched and even now, with barely passing the 4 million mark a year later has seen relatively little negative feedback when compared to what the 3DS received and what the Wii U is currently receiving.

I mean what if Sony or MS first launched their consoles a year b4 their competition? Would they be in a similar "slump"? Do gamers/people really trust those brands more then Nintendo?
Microsoft did with 360, no they were not in a similar slump. It's not really about the brands, its about the line ups and unfortunately, while the Wii U actually had a great line up, the line up was mostly ports. Though they were still ports of great games with some being slightly worse then then other versions and some being drastically better, the fact of the matter is ports are ports and people don't like buying what they already own. 360 had a lot of ports but they were ports of PC games that no other console had access to, which is an unfortunate problem for Wii U.

Or could it be because Nintendo has a "lack of games" for their consoles now and on the horizon?
It's not so much a lack of games, it's a lack of exclusives and this is indeed a big problem. With that said, there's some very big ones on the way that are completely exclusive to the system that as a gamer, I would get regardless of what platform they're on.

Or could their just be an overall slowdown in consumer buying in games/electroics because of the economy or other reasons?
Yes and no. It's not that consumers have slowed down or stopped buying, it's that during the holidays there was much better deals on other devices, systems and games, where as Wii U launched at full price and had all full priced games. If the economy doesn't shape up, this could also be a major problem for all the next generation systems, not just the Wii U. Also after the holidays, sales of everything slowdown greatly and don't pick up again till February/March.