Not everyone speaks English, far from it, but I totally understand the sentiment. In any case, even if you're visiting a place and you're awful at a language, it still means a LOT to the native speakers.
Yeah that's true it might be appreciated, though i'll add on and say i think its unreasonable to expect Americans to learn the local language when they travel. If i wanted to visit europe and go to 3 countries in 10 days, (i dont think thats an unreasonable trip) It would be crazy to do dedicated months of learning for that. Anything beyond, hello, good bye, excuse me and thank you is really too much and not a real good use of time.
There is a the real problem. There are too many languages in the world. All are nice in their own way, but nobody knows even 1% of all languages that are currently spoken. When I was in Germany nobody tried to talk to me in Spanish, if I met somebody who didn't speak English I just assumed communication was impossible even though Spain was only a couple hours drive away. I probably came off as a mono-lingual American even though I knew some Spanish.