I don't know about the US but in India, people who have a higher status in society or consider themselves to be superior use words like We, Us, etc. when they refer to themselves instead of I, me etc. What is the significance of this?
Of course there is nothing inherently wrong with the word "we." It is used to show positive relationships such as marriage, friendship, family, religious affiliation, and team. When "we" becomes an unthinking collective, however, there is potential for some really awful things. It is easy for racists to hide behind "we," and it is devastating to individualism to be absorbed into a "we" mentality. In society, the individual (the "I") must not be consumed by the group (the "we"). As mentioned above, Ayn Rand's Anthem is a great example of this.
In Anthem, Rand explores a utopia-like world. The narrator uses the first-person plural because that is what is comon in this society. The use of we emphasizes collectivism. The individual is nothing, but the group is everything. Each of us alone is less than all of us together, as emphasized by the motto:
“We are one in all and all in one./There are no men but only the great WE,/One, indivisible and forever.”
The usage of the plural form in India, is always associated with those of the higher caste and those with a higher social status. It sounds more like the speaker intends to say that I'm not just one like you, I'm twice as important as you are, hence the usage of "we" instead of "I". It is a lot more prevalent among members of the earlier generations, though the usage in modern society is coming down.
Originally, I think, English monarchs used "we" to mean "God and I," since kings and queens ruled by divine right. Kings and queens were rulers because God wanted them to be. Their right to rule came directly from God, it was believed.
In the United States, presidents frequently say "we" to indicate their administrations. Sometimes, I think, people say "we" to avoid sounding egotistical.
I'm not sure of all the relevant reasons why "we" would be used instead of I or me, but I can address one usage with regard to politicians and the like. The use of "we" could be considered a propaganda technique. When the President talks about the economy and how "we" must tighten our belts it's none as "plain folk" propaganda. They want the common man to think they're just like us and have the same concerns we do. If this is believed by the common man, then the politician has a better chance of achieving his or her personal agenda.
I have never experienced this..."we" is just considered to be the plural form of a personal pronoun which includes the speaker. I"ve never known it to be anything else.
Certainly it is common in Britain to denote the way that the Queen speaks. Analysing the History Plays of Shakespeare reveals a multiplicity of examples. I am not sure, but is the use of the royal we a reflection of the way that the King or Queen speaks for the entire nation, and thus is not classified as an individual? Would make sense...
I haven't ever seen a description or history of the reason why the use of "we" is less common in the US, but it is obviously still present. Certainly the president and other political figures have a tendency to do it when they speak but I rarely see people who are simply powerful or wealthy use it.
It was interesting to note the difference in Korea where it is used more often but in a different way, mainly implying that we are all in it together in most things that we do whether it is as a family or as a nation.
Well, there was the "royal we" that was used by people of extremely high status like kings and queens. They referred to themselves in that way because they were supposed to be representing something more than just their own physical selves -- they were supposed to be representing their whole nation. So they would call themselves "we" to indicate that they were in some way speaking for the whole nation.
As for people nowadays, I think they're trying to be more inclusive, at least here in the US. They're trying to make it sound like it's not just them making some decision but that, instead, they represent some consensus of their organization or firm.