Companies are going out of their way to ignore the fact that "the easiest way to stop piracy is not by putting antipiracy technology to work. It's by giving those people a service that's better than what they're receiving from the pirates." - Gabe Newell
I consider adblocking to be in the same boat. Piracy/Adblocking only exists because it's not a pricing issue. It's a service issue. By making the free version even more intrusive ON PURPOSE, they're not pushing as many people to buy a subscription as they are pushing people to install adblockers. If YouTube only ever showed a quick 10-15 sec ad at the very beginning of a video, I'd be less inclined to go out of my way to find and install an adblocker (and maybe even eventually just buy a subscription) than if they force feed me back to back, 30-second, unskippable ads.
It's the same with those stupid fucking commercials that run ALL the time and try and be as annoying as possible. If I find your ad to be annoying and frequent and shoved down my throat all the time, I will vehemently and actively go out of my way to AVOID that product, not be more inclined to buy it.