I think all copyright laws are really outdated and should be brought to the digital age.

That being said if we talk about the current state, fair use is great, but in some cases I kinda see it being an underhand way of dodging paying anything for the content being used.

Let say I start a company X, I want to use a famous song for my ad that will be played on internet. I have to pay this and that depending how much there will viewers and how long I'll be using the song and what is the length of the clip. In the end, that would cost a lot.

At the same time, there is a person who is reviewing movies by using clips from them and let say this one movie has the same song as the end credit song that I wanted to use in my ad. Keep in mind that the reviewer doesn't have to pay anything for the material being used. So as a company X, I could just pay the reviewer a few hundred (who's also getting money from YT views) to make him, in the middle of the review, advertise our company by doing a skit and tell him to use the end credit song in it (or just do a typical "sponsored by" before the show). There, I didn't have to pay anything for the music, only a little bit for the reviewer guy.

See how that's kinda unfair and that's happening alot these days. So that is why I can kinda see why studios and such would have a problem with it when people who do this professionally and make money out of your content and then hide behind fair use.

That being said, I still love Nostalgia Critic and other people who do this (since it's legal) and I think all current copyrights are outdated, but I'm just pointing out why fair use can be kinda messed up even though it's great.