I disagree with you, but especially the second part. Users advertise their interests by the subs they subscribe to, it would be very easy to target them. You could even go so far and let users up and downvote ads they think are relevant to them. The problem is more with the whole way reddit inc goes about how they interact with their users and power users. You shouldn't be openly hostile against your own users (except if you are the mods of askmen).
It really fascinates me that people think Reddit is hostile to their users, because when you really look at it, aren't reddit's users incredibly hostile to reddit management? Like really if you look at it from the outside you have this community that does this incredibly nasty things and then every time management steps in to try and correct it the community goes into uproar. I'm not saying the management have handled it well, but the userbase is a complete dumpster fire.
I'm not saying that at all - this API change has to do with business, nothing to do with personal feelings. But I just think it's interesting people criticise the leadership of reddit but look at what the users of reddit have been up to over the years - /r/jailbait, the harassment of Ellen Pao, the fappening, FatPeopleHate, the Boston bombing vigilantes, Pizzagate. Like yeah, sure, Reddit has been a total fuck up of a business proposition, but that really is partly because the site has harbored some really disgusting stuff over the years and it's only extremely recently that the company has even started to try to steer away from that stuff - and when they do large portions of the company react extremely badly.