OK, there are several issues here, and as usual they are being conflated.
(1) The bit about not being guaranteed a listing and not being guaranteed a permanent listing is true. We don't do that, and there's nothing you can get to get us to do that, and so far as it goes, that's the right answer.
(2) But we don't want listable sites being removed. So if that happens, your recourse is to ask about the site specifically, and we'll look at it. If (in the opinion of the reviewing editor) the site shouldn't have been removed, we can put it back -- we generally do that quickly -- and caution the editor who removed it. (If it happens multiple times, we appoint a new ex-editor.) This isn't your right as a webmaster, it's our commitment to the users to provide as comprehensive a directory as possible, and we can't have that with editors working at cross purposes.
(3) If you think an editor gets a more favorable response when trying to use his position to promote his site, you've got a wonderful fantasy. Abusive webmasters are just pestilential, but abusive editors are _treacherous_. If they persist, they are likely to get removed -- and a lot of the webmasters you see being treated least obsequiously in public forums are promoting ex-editors' sites. Editors can see each others' notes, which is not really helpful for cases like this: it doesn't matter why the editor said he deleted the site, all that matters is whether it should have been deleted, and that the note can't say. And editors had an abuse reporting system before the public did, but now everyone has the same access.
(4) Were you really wasting the editor's time asking for assurances that he could not possibly give, and that you should have known he could not possibly give? Absolutely you were!
Suppose the guidelines change, can the editor say "Oh, we can't bring up this listing to conform to the guidelines, I promised the webmaster!" Suppose the editor moves on to other activities, what will the next editor know or care of any foolish promises he might have made? Suppose another editor inappropriately (abusively) removes the site (it happens, as you know, although it is not so common as abusive webmasters think), would that editor be able to restrain the abuser? And how could he know ahead of time what sites would be abusively removed?
No, that was an inappropriate question, and it demanded a frank representation of my answer #1 (which is what you got -- perhaps a bit more tact wouldn't have hurt, although I'm probably not the person to say that). If you had asked, "what should I do if this happens again?", you should have received a representation of my issue #2.