Incorporating words from other languages is nothing new. It happens especially when different cultures morph together, and it is now more pervasive than ever with so many cultures coming together.
The origin of English itself was the result of invasions. Originally Germanic in origin, it quickly became something else when the Danes, Anglo-Saxons and Vikings invaded the area and eventually merged with the people and their Celtic languages and cultures. Eventually it bore less resemblance to its Germanic roots. There is of course more historical significance to the origin of English.
As cultures evolve, so do their languages. Now more than ever, language is evolving at an incredible rate. As Americanized products span the globe, and countries are becoming dollarized, their vocabularies change. For example the word "quarter" has now morphed into El Salvador as " Cora."
When added to a different language subtext, words adapt according to the sound and to accommodate the language. Words such as OK do well in any language because of their short length; however, a lengthy word which does not translate well due to pronunciation is less likely to be adapted into the language. New words from other languages come into the picture because they did not exist in that language; this is especially true for words for taste, birds, food or emotions. Words that express greeting can also be easily adapted from one language to another, however, sometimes the context changes.
Language can be adapted for illogical reasons, and become distorted along the way. l think of this as a little like a game I used to play when I was a child called "telephone", when you whispered a phrase in a circle, and by the time you got to the last child the phrase had completely changed. Language is a little like this; when we adapt a word to another language it becomes completely different especially if there is not a true understanding of the meaning in the language of origin. Eventually a combined language may evolve, such as French Creole, Patois, and pidgin English.
Cultural influences completely change language and, ultimately, the people who speak them. They are also socio-historical consequences to these changes, and some languages ( and cultures) become extinct in the process. This is well documented in the book Empires of the Word by Nicholas Ostler, which gives an overview on what various factors lead to languages surviving over time. Extinction can happen by overpopulation, conquest, or popular religion. Language can also be defunct yet still revered and studied by scholars (Latin and Aramaic).In the end, language, like the human race, will always continue to grow and progress like a never-ending quilt which tells of our amazing history.