Why do westerners (or say people in America) use a lot of superlatives, specially with regard to a state of well-being or praising somebody, even when the situation does not call for it?? Is it a sense of exaggeration or is it that they're simply used to it and can't shed the habit? Well, i'm not categorising them but this is just an observation of mine.

Quite contrary to us. We rarely use those words, or we've started to include them in our vocabulary.