Most of us are moderate on something, or neutral, and generally it's because we don't much care. Take me and legalizing pot. Theoretically I believe a human adult of sound mind can pretty much do whatever they want to themselves so long as it doesn't significantly endanger others. So drunk driving does as would setting yourself on fire or injecting yourself with some drug which effectively makes one a psychopath. Pot really doesn't do that, so I feel it should be legal. Yet I don't approve of its use and the smell nauseates me and the sub-culture around it bugs me, so my antipathy for the drug makes me at best indifferent towards its legalization. That's one type of 'moderation' and on that issue in particularly that's pretty common. The difference is that that style of moderate does not A) Feel good about being moderate or B) Think the pro/con arguments are silly and people should just get along.

There's another type of moderate that essentially extends from Apathy, though we avoid using 'apathy' for it. I am totally neutral about who becomes the next mayor of Somewhereville, ST. It has no significant effect on my life and I have no reason to learn about it, unless I live nearby or something really weird comes up. Lacking knowledge I remain neutral on the matter. Now, when that crosses the line into Apathy is when we speak of a grown adult who is not registered to vote, does not vote regularly, and does not have stances on major issues. These people are fine by me so long as they recognize that they are not experts and that they really have no business having an opinion until they do as the rest of us do and take some time to find out what is going on, hear both sides, etc. Many on hearing about an issue feel both sides have compelling arguments and remain neutral and torn. These type of moderates are also fine by me, even when they express their views. Almost all of us have a few views like that. Now many of us often settle on a viewpoint but still considering the other side respectable, feel they have points but that the net pro/con doesn't favor them. This is actually how most of us righties and lefties feel, but we do tend to get a bit drowned out by those who passionately believe the other side is dead wrong.

What I get ticked off about, and the OP had a strong whiff of that, was moderates who self-describe themselves as moderate and do so in a fashion implying that that is the enlightened stance, the superior one. I can't think of any issue that can really apply to and I think people use it a lot of times to cover over ignorance of the issues and a disinclination to learn about them, and it crosses a threshold for me when I feel someone is striking out at those with views essentially to justify their unwillingness to research a subject, contemplate it, or acknowledge their ignorance of the subject. This is the group I call 'moderate' when I'm using 'moderate' as a slur. Same as I don't mind someone telling me they don't know Special Relativity but I get a touch nasty if they start implying it's a useless piece of trivia not worth the effort of caring about. Putting this in terms, how would you feel about an argument on homeopathic remedies if someone stepped in with a smug expression and said "You both have some good points but we need to find a middle ground." and the next words out of their mouth make it clear that they don't know why you winced when they listed acetaminophen and Tylenol as two totally discreet headache medicines, think Salicylic acid is probably something you etch metal with, and now just enough about what a Placebo is to think sugar has healing powers? World's full of a lot of people who assume greater medical knowledge then they have and like to give advice, politics is much the same.

I think it basically comes down to "It's a complex issue". A phrase I often use and so do others. Difference being most of us use that to either preface a long explanation with a warning that it might be time-consuming and boring, or to avoid being sucked into an argument we do actually have an opinion on, or warn people off that we really don't wish to discuss the subject, or are just worried that any attempted explanation of the subject will fail to really explain it or possibly leave them more confused. It happens to be my default response to virtually every political or controversial issue outside of actual political events and this board. Because when weeks after you've explained something by saying "Really it's about the same radiation as you get eating a banana" you find out that person has stopped eating bananas you kinda wish you'd just evaded explanation entirely. What it's not for is people to use it to imply greater knowledge and enlightenment when they don't, for instance, actually know anything about vaccination or mercury toxicity beyond 'mercury not good'.