I don't believe anyone is "up in arms" about it, I myself question the validity of doing it this way, when no-one has ever accused Xenforo of being "slow" - EVER - it just isn't, so why make life harder for designers and admins than it has to be? Why remove designer flexibility when there is very little or no benefit for most sites?
The very first thing 90% of people do is change the look and feel, many do it themselves, and many others engage someone else to do it for them via a pre-made premium, or free theme or whatever. In the case of the Node Icons in particular, there is very little advantage gained by removing the single image link on 4 small images, and unless it is a dead simple change to convert it to a single image link (no idea if it is or not, not having seen the code for how it is done in 1.1) why remove this option for the sake of a miniscule time saving which would only be of benefit to a very few massive boards.
I guess my comments fall into the "It wasn't broke - why'd you
fix it" basket.
Again.. my 2 cents
No doubt Spritesheets are hear to stay, and no doubt I will learn to live with it as I have said. But questioning the decision doesn't make one "up in arms" about it, we're not children here.