The whole concept of the ignore feature is a big red herring that get's brought up a lot in this kind of thread as a pointless quick fix.
I rather see it as a good solution for small issues that don't require moderation. It means it spares the moderators extra work. How many times did this particular problem occur? It's the first time I see it here, and it's discrete enough to annoy only the person being harassed.
Use the good tool for the job at hand. It doesn't stop the victim or anyone else from calling a moderator if he thinks it's more adequate.
1. It redirects blame from the individual being harassed back to the individual. An implication that the abused is to blame for noticing they're being abused. Which is absurd.
I really don't see it that way. Nobody will blame someone for adding an annoying person to the ignore list. It's actually a wise move in comparison to responding and derailing a thread. It mimics what we should do on the street or at school when we're faced with someone annoying; in most cases, the offender will see that the bait didn't work and will give up.
2. It hides the abuse of any given system from the individual but not to everyone else. Much as we like to pretend we don't, but we all are prone to peer pressure, how others react. If 10 people are literally laughing at you every time you post, but you never see it, you'd naturally look stupider and stupider each time you posted and the number of people laughing at you would increase unchecked. It would very quickly become group think to join in the laughing, as there's no opposing counter.
That's a good point, though it's not the victim who'll look stupid but the offender. At least that's what I thought when I saw the thread in question, but let others give their opinion on that point.
If the group joins the laughing, then it probably means there's another, deeper problem that may have something to do with the poster.
3. It makes conversations ridiculous more quickly as people converse in different directions or repetitively, not having any clue that a previous poster has either already concluded a point or made the same point.
We're talking about ignoring someone's emojis, not his posts. However, it's true that in the general case, some messages are missed, but is that any different than a normal thread when nobody is ignored? People don't read all the posts, nor do they reply at the same time.
Quoting people is the best way to reply, for all those reasons. You can also check the post number to see if anyone posted between you and the original post.
Finally, you don't have to ignore people indefinitely, either. Just do it until the crisis has passed.
4. It actually enables abusers even more than the abused as it allows a user to post without ever having to witness the consequences of their actions, so they never get the opportunity to self-moderate. [...]
It's a false problem. Not everyone puts people on their ignore list, and even if it were the case, I doubt that someone would be mad enough to continue posting without getting any attention, because that's what he's after. It's what I wrote about about his bait nor working. Also, moderators are regularly reading posts, so it wouldn't last long.
5. The whole point of a forum is to exchange ideas, engage in discussion, help out with difficulties and, yes, sometimes have an argument or a joke. An argument isn't necessarily a negative thing, even if it gets heated.
Again, it's not necessary to ignore people indefinitely. I have put people on the list for one day, just because there could have been friction otherwise. Once I cooled off, I removed them from the list. But people who are constantly irritating someone would conveniently remain on that list (unless it's a clear case for moderation).
I think it's everyone's choice to either use that feature for peace of mind or to engage in arguments that are perhaps hopeless and not necessary.
If someone is ignoring someone because they don't like opposing views, then a forum likely isn't their ideal habitat.
Couldn't we say the same about moderation, then? Or, if you really think that, why do you think it's worth making a poll when a troll is throwing a few emojis? Probably because if there's a problem that is different than just a difference of opinion, it's not a question of habitat any more, and it requires other actions than arguing...
Moderation and the ignore list are just two ways to make the problem disappear, but with a different impact on the offender.
There's practically zero to be gained from ignoring other users, regardless of what happens when you ignore someone.
I think I've shown several situations where it's useful - it's all about gradation - but don't use it if you don't like it.