I can share my experience on this; firstly I lived in the southeast and northeast part of Brazil, and had (still have) a lot of friends of several states in Brazil, even though I didn´t travelled to many regions.
Historically we had a society that was comprised of mills´ Lords of sugar plantation (in the very begginning of our society) kinda nowadays society structure in some Arab and African countries, and a mix of some structure of ,say, then imperial Japan (the women part, not the cumpliments, of course).
In the firsts economical cycles (sugar cane and gold) we had a society where women were hidden when a visit came home while the coloured slaves were showed like trophies, poor things that your lords could "have fun with", no rights; segregation and prejudice were rife; Indians were regarded as lazy because they didn´t subdued.
As there weren´t not rights, the rule were the ruler himself and a slave or poor man (here white or coloured or whatever) didn´t expect thanks for a man of higher rank and this somewhat and to some degree still happens to this day.
The armed forces were constituted by rich men that bought your "officiality" in most of cases, and ,of course this was hereditary.
The police were in your majority black people and were used to maintain the order, in the sense that order were needed among the lower ranks, the coloured person to summarize it (so call a spade a spade).
There were no greetings and no farewells most of time, because slaves didn´t went to another state or even another farm, and the white women didn´t went out.
In Minas Gerais (a major state then, important because of gold commerce and extracting) there were the churches for whites (men of good will; in another words those that had the monies), churches to workers and churches to the slaves.
Thus, if a lord (owner of slave) gave a gift to a slave, the latter would be flabbergasted perhaps to the point of faint on the spot or hyperventilate, and would think that your lord had gone mad or something like that.
Still, farmers did think in the early 19th century (with the arriving of immigrants), that they were the owners of the fresh workers in the coffee farms. Obviously this led to a clash of civilizations (Europeans, mostly Italians didn´t accept this condition, taken for granted by Brazilian farmers).
With the urbanization of Sao Paulo and others states and many fights, industrialization and lacking hands to work, the Brazilian and other cultures came to a balance, at last.
So, it´s not surprising not receive cumpliments, thanks and farewells from a people that is in higher ranks or think that earn more than you or that have a job more "acceptable in society" than yours.
Other day, I gave an example of my brother is a teacher, he was expelled (had the option to comply to school rules ) from the scholl he teached because a pupil wanted mess his class, and dad was the rich man of city.
Another instance was when he worked to a city hall in town and decided change to another job, the mayor didn´t release him work papers (work permit, whatever..), so he went to Labour (Employment) Dept. and made himself another papers, work with these up to day.
In my humble opinion, some things here must change, may be even a bit; a teeny particle in our culture.
My part beggins here, calling people to learn English and some of good traits of it, ´cause, like any culture has its faults, it´s up to us discover and separate the tare from wheat.
For me, greetings, thankings and farewells are a welcome change, because I myself went in that "trap" and was misunderstood for English speakers.
I like knowing the mores of the person and yours country usages/etiquette, for example ; in Brazil is lack of education to belch at table, in some countries is an insult no to.
Before somebody jump to hastily conclusions, greetings , thankings and farewells are synonimous with politeness in Brazil, the problem is, some people aren´t totally accostumed to this usage, and a few think that is a nice thing....to others doing.
So long, and corrections, complements and other suggestions are welcome.