It may be the same in the sense that both hurts the creators, but blocking ads in today's internet is totally justified from my point of view. The intrusive and privacy invading nature of today's ads makes ad-blocking a necessity in my opinion.
It steals bandwidth and computing power. I spent money (and time and energy to earn that money) on my hardware and they are using it, degrading it without my consent. I want to use my hardware for whatever I want, I want the freedom to choose that. I don't want it render ads and shit like that.