Many Indian languages have multiple forms of the pronoun you -- a respectful version and a non-respectful one. In Telugu, for instance, you'd address your dad's friend meeru, and a taxi driver, nuvvu. Ditto in Hindi with aap and tum.
Not only is this more cumbersome than simply using one pronoun uniformly, giving more respect to a person tends to give more weight to what he says. We may like to think of ourselves as logical people, but we can't help colour a suggestion by our opinion of the source. A friend of mine did an interesting experiment at college. He wrote a poem, showed to a half-dozen people and asked them what they thought of it. He then showed to another set of people, but this time told them it's by Abraham Lincoln. Guess what? The second group found the poem better. So when someone tells you something, your opinion of the speaker definitely affects what you think of the comment itself. When society dictates that you give more respect to one person (a meeru) than another (a nuvvu), it's subtly forcing you to consider the meeru's views more correct than the nuvvu's.
Which is totally wrong. Ideas should be judged by their intrinsic value, and your opinion of the source, not others'. Or we have a society where the best ideas don't necessarily win.
As an example, I was reading a comment by an American software product manager or something about the respect Indian programmers give to the boss, and not speak up in his presence, losing out on good ideas that would benefit the project. And they (we) don't convey bad news to the boss, instead telling him what he wants to hear, wasting time and resources going on the wrong path.
Too much respect is a net negative.