What I'm entitled to is to do whatever I want with every bit of data I download through my browser. The day this stops being the way things are, is the day the web dies, and I can't believe anyone (particularly here) could be defending that.
YouTube provides their data freely. You don't have to sign-up or accept a contract. You open a link and locally download said data. It's on my device, and I control my device, not Google. I can do whatever I want with the data I download, I can make the background pink, I can change some text for something else, and I can take out the parts that I don't like, like ads.
If YouTube wants to stop providing their data with no strings attached, they can. Reddit didn't like the way many of their users used their API, so they blocked it, and I don't use Reddit anymore. If someone doesn't like the way the open web works, they are free to leave, but they can't change the rules.
You ask why we are entitled to ad-free viewing. I ask why do you think Google is entitled to dictate what I do with the local files in my personal device. Do you feel entitled to open your browser's dev tools right now and modify this comment I just wrote?