Ethics don't don't come into it.
If you have good content I'll pay to see it. Don't need frustrating irrelevant ads getting in the way.
And yes targeted ads are a fantasy. They don't exist. I'm a huge Amazon shopper and they cant even get "Due to your shopping habits you might be interest in..." lists right so what chance so who are the ad networks trying to kid?
The only web folks that are worried about this are the ones that just steal and link to other superior content. They can die off today for all I care. Either provide it for free or if you want to get paid for it, make people pay for it. You might be surprised.