A lot of the free content on the Internet is paid for by advertising. Most of us understand this and accept some advertising in exchange for access to free services.
I accept some advertising in exchange for access to free services. I do not accept advertising that I find intrusive, annoying, offensive or overwhelming. I can do this because I use tools to keep the advertisements from making it to my computer.
This makes some people, particularly those who are relying on advertising as a source of income, very angry. Those people want me to accept advertising as a cost of doing business and they do not want me to have the ability to turn their advertisements off.
To those people, I say: Phbttt!
Okay, I don't usually start out with that, but well, you know some of them get really obnoxious about it and seem to be missing the absolutely essential point that my computer should do what I want, not what someone else wants.
If you want my computer to show me your advertisement, then give me incentive to have my computer download it and show it to me. I'm agreeable to viewing some advertising. So long as you show me things that I might be interested in and don't irritate or offend me, we can keep an easy partnership: I see your ads, you get revenue from my accepting them.
The moment, the very second, I see an advertising for a bogus anti-virus program or mail order bride is the moment I end that partnership. I never had an obligation to view your ad, now I will choose not to. Until you pay for my computer and my Internet connection and time, and I agree to it, you do not get to dictate what I see.
I appreciate the ease of blocking advertising that Adblock Plus gives me. Annoying ads are blocked by default and I can block any that dodge the block which I still find offensive.
Further, I block in my DNS server by using a hosts file described in various places.