I rather suspect that there is no actual hostility involved and disbelief is simply being expressed instead. Furthermore, I also imagine changes such as this lead some people to question past and future design choices and plot elements. I've suspected for a while that story direction may change drastically based on 'feels' and so I don't like such a mentality to be pandered to. Let alone when it's dressed up in a way to encourage people to rush to proclaim how amazing the development team is for being so thoughtful.

To say nothing of the fact that some people may simply prefer the old design to the new one.