I have found that people vary greatly from country to country, and that even a country with a reputation for being friendly can have its unfriendly moments. This is why I question any sweeping generalizations about how “friendly” a people are. For example, I spent some time in Nepal and found the people to be overwhelmingly nice, but this doesn’t mean that the same experience will apply to everyone.
Friendly and polite are often mistaken for one another, but they are quite different. I have met many polite people who I wouldn’t feel comfortable around; and many friendly people who are not necessarily polite.
I have heard reports from people of color, Arab and Asians who have had some very bad experiences in some places due to blatant racism. This is why I always question any statement that “X nationality is very friendly”. I find that how people treat their friends doesn’t vary that much from country to country, but how they treat strangers, acquaintances, and foreigners does. It could be that the culture encourages a greater social distance with strangers or outsiders, and this could be related to sexism, racism, classism, homophobia, etc. that manifest in a society and can greatly affect experiences at the individual level.
It is clear that “friendly” is often a stand-in for “accommodating to tourists”, especially when those working in the tourism industry have no choice. This is why it is important to be aware of the differences between friendly and polite, and to question any sweeping statements about a nation’s people. Everyone’s experience will be different and it is important to keep an open mind.