You guys are aware that the particular software that started this insanity, some crappy survival game (Day One: Garry's Incident), lost its publicity war with TotalBiscuit, right?
Except that Wild Game Studios (the guys behind Day One) weren't the ones who "started this insanity". This started long before the "Garry's Incident Incident", and from much larger companies. It may well even go further back than what I'm aware of (I wouldn't be surprised).
In November 2012 Sega totally blitzed Youtube, taking down loads of videos that had anything to do with Shining Force - this wasn't limited to let's plays and so on, but they targeted ANYTHING, even if it was just a video of someone talking about the game series with
no gameplay footage whatsoever (how that counts as a copyright violation, I've no idea, but Sega still had the videos taken down and the videos' owners being given copyright strikes and possibly having their channel shut down if they got 3+ copyright strikes). Exactly why, I'm not sure - supposedly Sega's official stance was that they "didn't want consumers to be confused over the older games and the new one", while some people reckon they just abused the copyright system to ensure their promo video for the new game in the series would appear at the top of search results.
In May 2013 Nintendo decided to start claiming that videos with any gameplay footage of Nintendo games should have all their ad revenue directed straight into Nintendo's pocket. Amusingly, TotalBiscuit actually got caught up in this as well, with Nintendo being ballsy enough to claim the ad revenue for an episode of TB's "TGS Podcast" - the 3-hour long video contained a 30-second trailer for a Pokemon game, so clearly Nintendo deserved every penny of ad revenue for the entire show, right?
The team at Polaris edited out the trailer and re-uploaded the video so Nintendo couldn't continue with their scummy tactics.
Although it was reported a month later that they'd not followed through with these plans, Nintendo apparently haven't stopped. More on this further down...
The "Garry's Incident Incident" was the next big story, in October 2013. This was mostly blown up just because the dev was a lying dick. He'd given TB a steam key to evaluate the game and post a Youtube video about it (which he was OK with provided TB added a link to the Steam store page so people watching the video could buy the game after watching it). He'd also given express permission to another user on Steam's forums that making Youtube videos was fine. He claimed TB's video was removed because "TotalBiscuit has no right to make advertising revenue with our license" while claiming that Kotaku's videos were totally fine because they "weren't monetised" (not directly on Youtube, but their website the videos were embedded on was packed with ads) and ignoring any users who pointed out any other monetised videos of the game (let's plays and the like). Ultimately, TB won because his critique is protected under fair use and the video was reinstated with a half-hearted 'apology'.
In December 2013 there was then a wide-sweeping content ID blitz right across the board, similar to the Nintendo thing from six months earlier. This led to several companies (including the likes of Blizzard, Ubisoft and Capcom) saying in public channels like Twitter that they had not requested Youtube do anything like that and they advised anyone affected to appeal and they'd quickly resolve the situation. This particular incident was what caused a number of companies to publish a video or Youtube policy that people could use if a similar event were to happen in future, such as
Codemasters' one here that explicitly grants permission for people to post videos on Youtube and monetise them. After all, for any
honest dev who's made a semi-decent game, these videos serve as free advertising so there shouldn't really be any significant reason for them to attack Youtubers.
Ultimately, people don't want to spend months or years of their life building up a 'brand' on Youtube, so there are a number of people who'll now only make videos of games made by devs who have given permission for monetisation.
Then TotalBiscuit got personally attacked again in February 2014, this time for Guise of the Wolf. This whole incident was so surreal, even now I kind of look back on it and wonder "Did this really happen?" and "Can a dev really be THIS stupid?". The game's devs (FUN Creators) claimed copyright to take down TB's critique and the accompanying research video. The devs denied taking it down, so a VP at Maker (the parent network TB works for) joined in saying that FUN had taken it down. The dev then claimed an email TB posted on Twitter was photoshopped, claimed they were being blackmailed, and they also posted blatantly photoshopped images to mock TB. They said lots of stuff on Twitter (now deleted) including "Our company is a lot bigger than your little youtube channel". FUN ultimately threatened that TB delete all his tweets and his Youtube channel or they'd file a lawsuit against him, so TB let Maker/Polaris' lawyers deal with it. The videos went back up, nothing else was really said about it from either party until a co-optional podcast a couple of months later when someone asked what happened with the Guise situation and TB's response was something along the lines of "Well...we actually had lawyers. They didn't.". FUN continue to heavily moderate the Steam forum to remove negative comments about their game, and in the past I've seen that they've flagged negative reviews on Steam as "abusive" even if the review just says something like "Nope".
And now back to Nintendo. In May 2013 they had a content ID sweep which pissed people off, then in June 2013 it was reported that they weren't following through with that. However, in the past month or so they've gone back to trying to grab advertising revenue from Youtubers. They've set up some affiliate program with Youtube where the content creator's share of ad revenue is split between the content creator and Nintendo. They then set about flagging videos en masse yet again. Apparently, those who are not in this affiliate program have had their content of things like Mario Kart 8 getting flagged for using copyrighted music, with all the ad revenue going to Nintendo (so it seems Ninty want the situation to be that either you agree to give them some of your ad revenue or they'll take it all)