First off, I'm not one of those people whom regularly complain about YouTube or it's advertisements. Some level of advertising is good; it encourages companies and individuals to post more content.
BUT... the other day I was listening\watching a music video and simultaneously, a freaking Air Wick commercial was playing at the side!
Video commercials WHILE watching? How am I supposed to listen to two videos simultaneously?
This type of advertising is pointless. Everyone is going to find a way to mute the ad that's interrupting their video. Additionally, it makes everyone hate YouTube and advertisers that do this.
I've also seen this type of advertising on website articles. How am I supposed to read your article when a video is playing on the side? The first thing I'm going to do is mute it! It's completely pointless and detrimental.
Overall, this is a very surprising move by Google. If you use any of their services (search, Chrome, Gmail), Google's 100% about user experience. I predict over time, they will come to their senses and get rid of these type of ads.