If I don't block ads, then I'm stealing from the advertiser who's paying per impression to someone who isn't interested in their crap.
If the ad makes noise, moves around the screen, crashes my browser, or otherwise actively interferes with my ability to obtain the information I was looking for, It'll leave me with such a negative impression that I won't buy anything from that brand, now or ever -- or from the creator who allowed them to break an otherwise good website.
So really, by blocking ads, I'm defending the good reputation of both creators and their sponsors.