First of all, content blocking in iOS has a ways to go. It works in Safari and Safari View Controllers, and since as far as I know these new view controllers only got added this year, most apps which use web content won't be using them and thus won't be filtered by blockers. Since most of the web content I consume comes via RSS readers and social media apps like Twitter, Facebook and Google+ the content isn't filtered until they decide they want to adopt the new controllers (if they ever do). I don't really want to push every web link out to Safari because of the overhead of then having to deal with tab management instead of just reading and swiping backwards or tapping the close button to return to a feed.
The ethics of content blocking are... difficult. I feel very conflicted about who the blame lies with. Advertisers definitely shoulder most of the blame for resorting to generally scummy practices to track users and circumvent their wishes. Publishers deserve some of the blame for accepting money from advertisers who resort to these practices. If they can't afford to sustain themselves by methods that don't abuse their readership, then that's business. At the same time, readers who want to read the content should contribute to some upkeep of the publisher's content, although there is no case for advertisers tracking their behavior without their knowledge or consent or some way to opt out before proceeding.
The really sad part about this is some sites implementing tech to get around content blockers to display ads regardless. If they want to detect blockers and just display something to the effect of "ad blocking? Nothing to see here then" then fine, but really, take the hint.
Back when there was some kerfuffle about BuzzFeed doing "native advertising" (i.e. Sponsored articles which weren't necessarily overtly put forward as advertising) I thought it was pretty despicable, but at least people had the choice whether or not to pay attention (or even load the page). Other methods which smaller businesses have used which I think are more effective are monthly sponsorships of things like RSS feeds, ad reads in podcasts and so on. I find I pay far more attention to them since they are less frequent and tend to be chosen by the publisher according to their audience rather than dictated by the ad network based on search data and profiling.