I'd think that this sign is not there because of American tourists. All the Americans I've met while traveling, have acknowledged that English being their native language is a privilege and have been very polite towards people who don't speak English that well. But in Europe English has become the universal language and it's easy to forget that not everyone can speak it as well.
I was responding to the title, which was typed by OP, not to the image. I don't know why you responded as if my comment was directed at the image instead...?
I certainly don't. It's a huge part (besides cost) of why I find the prospect of travelling to other countries to be very intimidating. I don't want to be a pain in the ass for the locals when I can't communicate with them properly.