I think it is important that people know where their food is coming from,and that they appreciate that meat comes from farmed or hunted animals, and I suppose if you have only been exposed to packaged joints or packages of sausages from the fridges of the supermarkets then people might not appreciate that meat comes from animals.
As to the specifics of that display; People are entitled to complain if they see something in a window store that they object to; This is, after all, a democracy. And I personally found the display somewhat distasteful, even though I have worked in butchers and abbatoirs in my younger years.
But the butchers could have ignored the complaints; they could have been a bit more robust, stuck to their guns. After all, they have claimed to have a lot of local support- indeed, they claim that the majority of locals support them - so why not continue with what they were doing? I find it strange that butchers were sufficiently intimidated that they felt it necessary to take down the display.