The "offensive" flag is reserved for extreme cases of abuse or hate speech:
When should the Offensive flag be used?
Even if a post is a bad post for some reason or other, it is probably not offensive. The Offensive flag is meant to be used only in extreme cases, like hate speech, or abuse.
For example, if a user posts obscene images to the site, that should be flagged as offensive. But if someone says something bad about your favorite technology, that probably doesn't apply.
As a rule of thumb, if you can't justify something as being hate speech, or abuse, you shouldn't mark the post as offensive. Instead, you should down-vote the post.
When you decide to flag a post Offensive, you will get a warning dialog. Take this time to decide if the post is really offensive.
Also see the accepted answer to Is belittling language offensive?:
It's offensive if you feel offended when reading it. In which case, feel free to flag it.
But remember, just because something offends you doesn't mean it offends anyone else. If enough other users flag in kind, the comment will be removed. If a moderator flags in kind, it will be removed. If no one else cares, or if a moderator disagrees, your flag will evaporate...
...But really, that's none of your concern. If you honestly and truly feel that a particular comment is harmful, you owe it to yourself to flag it. Then... move on. You'll feel better if you don't get hung up on it.
Bottom line: You are welcome to flag comments that you perceive as offensive, but offensiveness is often a matter of perspective, and your flags are simply another kind of vote. Whether it's on main, meta, or chat, people need to agree with your flags (i.e. by flagging in kind) in order for them to have any effect. If that doesn't happen, they'll simply age away after a few days.
While hobodave's comment may not have been particularly tactful, I'm sorry to say that I don't think it meets the bar for "offensive". There are other members who use chat, and evidently they didn't agree; given an escalation (such as this meta post), all we can do is try to apply the "reasonable person" test, and I am not convinced that a reasonable person would find the phrase "steaming pile" to be offensive to the degree of hate speech or verbal abuse.
It's not even entirely clear that he's referring specifically to the question; in fact, I read it as applying to the entire thread, not focused on the question itself or any particular post. The answers were not high-quality; in fact, they triggered several automated "low quality" flags if memory serves.
Also, all of the above applies to posts/comments on the site. Chat is intended to be a lot more liberal. Offensive flags in chat should generally be reserved for open-and-shut cases, like long strings of cursing or racial slurs. Any other flags are probably going to be ignored or dismissed.
On one final note:
I asked a poll question knowing it would be closed.
Yes, you did, and this isn't appropriate behaviour. Experienced members should be helping to moderate the problems, not add to them when they know better. The question in reference was a fairly egregious breaching experiment - as in, "let's see how many answers and votes I can get before this gets closed". Please, do not litter the site with these.