My opinion is this...
http://www.youtube.com <-- see that? It's YouTube. You can view this site, and watch some videos on your PC, Mac, or whatever. So, why the heck is it SO necessary for it to be on the 3DS? Apart from, as I've said before, "OMG luk mommy i have uchewb on mah 3ds omg!"
We don't NEED YouTube on the 3DS, when you already have YouTube on the PC. I the constant complainers stop expecting the 3DS to be the world's most powerful multi-media dervice. It's a game system. They should just be glad we have a browser at all, or a video service.
Seriously, if you want to use YouTube, use a PC, or whatever. 3DS doesn't have Flash or HTML5? Well, the world is over now. The Browser on the 3DS was mainly created so you could look up walkthroughs from sites like GameFAQs etc, and to browse sites with that format which some of you MAY remember, infact, I'm using it now. It's called text... it was NOT designed for freaking watching "Robotnik's Pingas Machine 3D", or to play [insert well known Flash game here].
Seriously, what does everyone want?
A 50 inch 3D screen at 4320p (Ultra HD), with a 22.2 surround sound system, with 20 Gigabytes of RAM, and a 5 terabyte hard drive, with a 100 hour battery life, and graphics that make the Crytek's graphics engines look worse than that of an Atari 2600 game, capable of running at over 5000 frames per second?
Well this is my opinion. Or in short... I don't care. I'm not really THAT bothered that we can't watch YouTube on our 3DS. What's the big deal anyway?