...And that's a bad thing because?

Well those are the only two currently announced games with potential to move significant amounts of hardware. If Mario & Smash Bros dont increase console sales then it is very unlikely games like Bayonetta 2, Sonic Boom, X, Hyrule Warriors will.

With that said it does annoy me when people say we will have another 6 month drought after Mario Kart since there are a decent amount of exclusives that will release in between.

Because they're the only system sellers for the system this year? The Wii U has some great exclusives for it coming out for it this year, but those 2 are by far the most notable due to their potential to move units. I doubt X and Bayonetta 2 will be able to duplicate the effect.

Because it makes sense. Does anyone actually believe that Nintendo will show nothing new at E3 and have only Smash Bros for the Holidays? 

If we can expect a COD based off of history, we can also expect Nintendo to release more than 5 games in a year. (Based off history)

I dunno man, you see, looking at statments made by iwata and myamoto in the past, and the development on this gen so far, it's really hard to me to believe that they have all those unnanounced exclusive gorgeus games in the oven baking for more than 3~4 year now, harder yet is to believe taht will be in the lines of f-zero, stafox, oreven something new. The statments they had on the last investor meeting painted a different picture:

1. Myamoto believes that the problem of WiiU lacking games is solved. Hes not talking about only quantity, but quality too, based on the praise SM3DW recieved, and even managed to sell > 1mil before the year ended. This is not something new when come to nintedo. Back in the n64 times they had like 12~13 releasinga  year, while PS recieved more than 100. They actually believe that is most important to make 1~2 blow way games than 3~4 good games. See their focus is so strong on SSB and MK?
2. Myamoto also stated that they will "put resources" on QoL to develop something fun(can even be the new IP that he mentioned before), so is not like they are focusing on how can we save wiiu, and more like how can we save ourselves?
3. Iwata believed that they have to focus more on the gamepad, and pointed the revealing of games that use nfc in this e3, so i will not rule out the possibility that all new games(if its more than one, wich i doubt a litle) for wiiu will something in the lines of animal crossing with nfc toys.
4. Nintendo almost only talk about MK and SBB. Back in may, kamiya complained that he was somewhat disapointed with the lack of effort that nintendo put on promoting W101. He said that not many magazines had previews of the game, and everything that nintendo made to promote the game was actually his idea. The site was his idea and he mentioned that a lot of people with he talked tough that the game was about dogs(in japanese sounded like that). The direct? His idea. Remenber that nintendo made a TV ad of pikmin 3? W101 saw nothing of it. Some argued that X was the best game nitenndo showed at e3. The problem is, at e3 nintendo booth, there was nothing about it. They were showing 3DS, and even Planes(tie-in of the film), they even bring someone to do cosplay of bayonetta, but there was no sign of X. SBB was announced at e3 2012, altough the first footage emerged on 2013 e3. Since then, we saw the release of a screnshot everyday. We see the release of  a new pic about a new track on MK every 2 weeks. Nintnedo only mentioned X 3 times. Bayonetta 2 close to five, we are supposed to recieve those games before SSB WiiU yet we still have no idea about the story on X or more information about Bayonetta gameplay style. Remenber Yarn yoshi? Or the fire emblem crossover? And zelda musou? What nitnendo has talked about those games after the release of DK?

I actually expect the reveal of the new zelda, but i really don't believe that they will something totally not expected for WiiU(read: ceasing production/cuting price and making bundles is not unexpected)

All of this is true but the system is $300 still. I can't imagine Nintendo discontinuing support for it already. I think they are saving all updates / new stuff for E3. They are just riding on the MK & SSB hype for now.

We can be pretty sure. Nintendo's major currently active home console IPs (what matters most for them right now) are NSMB, 3D Mario, Zelda, DK, MK and SSB. Of those 6, NSMB, 3D Mario and DK have all failed to pull the WiiU out of it's current hole, which just leaves the other three. Considering how much more popular MK and SSB are than Zelda, i think most can agree that if neither of them is able to help the WiiU, then Zelda won't be much use either. Hence everyone's interest in seeing how those 2 do.

That's all you got exclusive for the XBO? Poor XBO, not even B. King thinks you're going to have a bombastic Holiday.

OT: Because they are Mario Kart and Super Smash Bros. Just saying those beside an upcoming Nintendo console will ensue money throwing. (In the correct direction, not down the trash.)

thats not what you asked. You asked how come people expect more from E3 from the other two than SOny and MS. they expect more, cause history has shown they have GIVEN us more its that easy. I dont know what Ninty will show to be honest, but again you ignore that they werent even AT e3 last year. So if they show nothing new at all...i wouldnt be surprised.

I expect COD because that is a yearly franchise, does Ninty have any yearly franchises?

They had the direct so they still had a presentation with new games. 

As for a yearly franchise? It used to be Mario Party but not anymore. Although, now that they have that new team that does them, You can probably expect a Mario / Wii party this year.

I asked why do people count everything for the other two but not for the Wii U. I got an answer I'm happy with already though.