It was banned in Turkey until 2010, due to a lot of videos insulting Ataturk. It was later lifted.
Creator Backlash: The uploader of the first video on Youtube, jawed, didn't seem happy with Google Plus' integration into Youtube, with comments such as "why the fuck do i need a google+ account to comment on a video?" and "I can't comment here anymore, since I don't want a google+ account.".
Over the years, YouTube has shown more and more favoritism and preference to partner channels, or channels that have a significant amount of subscribers or viewer activity. For example: are you just an average joe posting videos of things you find interesting or amusing? Well, good luck generating traffic on your videos, because they won't even show up in the search results, regardless of what tags/keywords you put on them. Want to access certain relatively new features, like checking out "audience" or unlocking custom thumbnails? You'll need a ton of subscribers and a lot of people watching your videos all the time, otherwise, those features will be locked to you. In other words, if you're not a partner channel or a regular channel that generates a lot of activity, good luck trying to get any kind of notice, because YouTube has pretty much swept you under the rug.
For channels that are partnered, YouTube made changes to their Content ID copyright identification system in late 2013, making it more difficult to monetize videos. As Content ID was already considered "judge, jury & executioner" by critics before the change, this has lead some partners to threaten a move to another video sharing site.
For reviewers of media (such as games, movies and music), the changes are even worse, as YouTube never seemed to like the idea of fair use.
What Could Have Been: The site was originally a video version of a website called Hot or Not, where users upload picures of themselves and other users would decide whether or not the user is hot or not. However, the creators found this too limited, and later made it a general video site.
Why Fandom Can't Have Nice Things: The founders reportedly said in several interviews that they sold the website off because of hordes of teenagersnote the aforementioned users uploading copyrighted material on it (instead of making their own videos) and ignoring its rules, thus destroying their dream for a youtube.
This came to bite them in the ass all those years later, when Google+ became mandatory and they asked why the hell they were being forced into this.