So - I actually agree with you on this one. Aproaching another creators wall and saying "hey read my stuff" is a lot different from approaching a readers wall. The creator has an image to maintain while a normal reader is just sorta there.
That said - I think this direct marketing approach probably isn't a good use of anyones time? Like - here's everything that you have to do to make this effective:
1) develop an ad post
2) find the readers you want to advertise to
3) go to each of those readers walls by hand to make the post.
Then consider that most readers don't even use the desktop version of the site and as a result don't have access to their wall - and that even those that do use the site may not know or care about their wall - and then even those who care about their wall may not care about your advertisement. It just feels really innefective to me.
It's like if you were a door to door salesman but 60% of the houses you visited didn't have a door, and also the residents are all out of town right now. It would probably be a complete waste of your advertising efforts - unless you somehow took advantage of the benefits of such a direct medium (for example, opening up direct discussions with these readers on their home turf).
It doesn't really matter if people find it annoying or not - it's just an inherently innefective tactic.
I've been popping in this thread a lot with my perspective on things and now is probably a good time to mention that I'm currently in a marketing/advertising/social-media program at my college. So like - I dunno I'm not completely full of shit I guess.