My experience in Indonesia has mostly been lavish thanks from peers that I've helped - it is true that the thanks from staff for generous gifts are perhaps a BIT subdued. But with the exception of one individual, who has annoyed the crap out of me because I did a lot for him and rarely got even a minimal "thanks," I've felt fine about the expressions of thankfulness. (The one individual is extremely Javanese though - he's from Sragen. I have always assumed he's a bit of a jerk in some ways, but maybe I've been overlooking a cultural explanation all along.)
The nationality that doesn't say "thank you", in my experience, is Mozambican (I lived there for a while, 1997-2001). A long time ago (maybe 15 years or so) there were terrible floods in Mozambique, and a bunch of South African pilots flew daring helicopter rescue missions out of the goodness of their hearts to save people. I do remember one news story about it, where they quoted a pilot as saying, "and when they got out of the helicopter, they were so exhausted they didn't even say thank you for the rescue." I thought that was diplomatic. In his heart, the pilot was probably thinking, "I'm glad I saved them, but boy were they assholes."
As always, it's just a cultural thing. It was explained to me that people in need don't say "thank you" because it means, "that's enough, I don't need anything more." That country was so poor that EVERYBODY always needed more. It was a pretty tragic place to live - and I wasn't there for the worst of it, things were getting better by 1997. Still, it was heartbreakingly poor.