For me, it would depend on the type of icing. I can't stand Mock-cream icing where they simply mix butter and icing sugar then whip it until it resembles cream.
I also severely dislike icing if it is too sweet - there's nothing worse than eating something only to have that cloying feeling in the back of your throat :yuck:.
Apart from that, I do enjoy my icing - in moderation of course!
I think icing is okay but I prefer the cake that it typically goes on much better. I usually just lick all the icing off of the cake and eat the cake by itself because I don't like the way cake tastes with the icing on it, it just doesn't go together well. I especially hate when they put tons of it on, if they're gonna put on any icing I prefer it to be a minimal amount.
I'm quite picky with icing. I'm a cooking fan and I tend to use icing a lot, but only if it's exactly the right taste, thickness, and colour. Once, I actually had to re-do it three times before I got it right. I make normal icing with some vanilla sugar and bitter almond extract, and that doesn't make it too sweet.
I like icing, but I do agree with you Azure Sage. It is a bit too sugary and rich, which is why I make sure that there is a thin layer of icing before I eat something that has icing. I feel so sorry for you on how your body reacts to icing. I do hope that will never happen again to a close buddy of mine.