There aren't any other companies with IPs as strong, notorious and long lasting at Nintendo's. So that should tell you enough and answer your question.

LOL...Says the company that tried to license Disney's product when they were a card company.

No, they just aren't dependent on a few strong IP's as much, so the potential benefits outweigh any IP damage. Square-Enix is an example of another corporation that can experience IP damage, and Square-Enix does things very similar to Nintendo. Square-Enix does things on a game to game basis, like Nintendo. For a while they were taking down monetized FFXIV videos. They changed their position, but they still continue to do said things for certain games. The only difference is Square-Enix didn't make a  method to their interactions with youtubers like Nintendo.  

http://www.pcgamer.com/square-enix-reverses-policy-on-final-fantasy-xiv-video-monetization/

"You may not use the Materials for any sales or commercial use, meaning you cannot receive license fees or advertising revenue, except as part of the partner programs operated by YouTube.com, Twitch.tv, Ustream.tv, or similar programs. If the operator of a partner program seeks to confirm our policy, please point them to this page as we do not have the resources to respond to all requests."

I don't feel bad tbh, Nintendo owns the content, they laid out the rules of how to use their content. He didn't do it, so they claimed it. Props Nintendo, stick with your guns.

Yes, the quotation means, you cannot gain ad revenue on a Nintendo product unless Nintendo gets a cut (like they need it). The Youtubers don't make as much as most think. They are really doing this because they love it.

If I was Nintendo I would set aside the strongest upcoming games they have and send them to the strongest Nintendo based Youtubers out there who support what they are doing because it is noticable publicity. They need all the publicity they can get and I suggest they look for the most powerful youtubers under their policy who can show off their product with their sanctions.

Here's a bit of hard reality for you, Nintendo. Keep living and making consoles like it's 2006 and your NX will fail just as hard as the Wii U. Not in an era where gamers, as well as Sony and MS, have embraced game streaming as the free advertising that it is.

I mean, you do have them doing pretty much exactly that by inviting Youtubers like ProJared and GameXPlain to their events to capture footage on Splatoon to upload to their channels...

The quotation is SE's policy, not Nintendo's. Anyway, if let's players who do let's plays as their only source of income don't make much money as Youtube celebrities shouldn't they find a job which will allow them to pay their expenses while still doing let's play's as a part time thing/hobby for a little extra cash? Maybe they can join a professional video game review/walkthrough company and have an annual salary? I mean if Angry Joe, for example, really only spends sixty hours per video that is only something like 800 hours per year on average, according to his video count and the first video review he created. Most people work 2100 hours per year. So for every one hour AngryJoe works the average person works almost three more. This includes the people at NIntendo who are doing their job developing games and who are expected to have some of their games sell well to cover the costs, or otherwise they might be laid off. I mean it is only fair that if a property is being used as a means of production that the person who's property is being used is compensated in addition to the person enacting said production. This is the standard in all industries. 

I cannot advocate ad revenue for lets players, because all they are doing is playing the game and the content is not being used for a creative voice. Should they get paid? Thats up for debate (for me? No), but Angry Joes views mostly come from reviews and commentary, not Lets Plays. Actually his least popular views come from Lets Plays.

You don't know how many hours Angry Joe works. He has to record and edit his videos, which could probably take longer than most peoples eight hour days. He tends not to cut down his edits. He has literally a set at his house. This has become his life as well as for other Youtubers and you can tell by the quality of his production value in his games that he spends quite a bit of hours on them, including the acting, green screening, VFX, editing, Website and much, much more.