I can understand this feeling as a fellow 'Merican, but also having lived abroad, I also understand how it's good make language barriers visible. The reverse of this happened recently in my former town in Cambodia, where there is a lot of tourism, but yet much of the local population still don't speak English, Spanish, or Chinese, the big three tourist languages there.
Some shops put up signs that read "Khmer/Chinese only", or "Khmer/Chinese/English spoken here", etc. There was recently a violent attack by a white westerner on a Cambodian shop owner who spoke no English, and it all arose from a language barrier.
The whole thing was recorded on video with audio, so as a Khmer-English speaker I was curious to see where things went wrong. It was clear from the outside that this shop was on the edge of town and had no English language signs. The guy asked for a case of water in a very lazy American accent, and the shop-owner responded by saying "I don't understand" and "I don't have it" in Cambodian.
They guy then began cussing her out telling her he can see she sells water, and she's a racist for not serving him, etc. If she had a sign up that said "Khmer Only Spoken Here," perhaps this situation could've been averted. I guess what I'm saying is that it's all about the intentions behind any action, and that's what we need to be looking into.
On a lighter note, I'm immigration to Kentucky/Indiana with my Khmer family, and we've been roleplaying situations where someone will approach us in Wal-Mart and tell us to "stop speaking ching-chong bing-bong because this 'Merica and we speak English!" Well, let's just say even though my family doesn't speak great English, they can easily roast any American that gives them a hard time, so I think we're safe, and I can't way to see a Kentuckian get roasted by a Cambodian in a Wal-Mart.