Resisting mixed language in literature

The resistance to mixing languages in a single work of literature comes not from the great writers (who have all done it, unconsciously or consciously), but from lesser writers more interested in ideology or politics than in being true to reality. Here, for instance, is a historical instance of writers trying to keep Belarusian free from the pervasive influence of Russian:

"Popular is the mixed language which is called ‘trasianka’ (e.g. ‘stirred language), it is the mixture of Russian and Belarusian but many people who speak it are sure they speak pure Russian. In the beginning of the nineties there was even suggestion to recognize ‘trasianka’ as a state language. ...

"One of the first examples of Belarusian literature is Francišak Skaryna’s translation of Bible, printed in Prague in 1517-1519. It was the third printed Bible after the German and Czech ones in Europe. Important too are the Lithuanian Chronicles and the Lithuanian Statute (the first in the world prototype of modern Constitutions), numerous church writings all dating from the 16th century. After the establishment of the Uniat (Greek Catholic) Church and making union with Poland, Belarusian language began to be strongly polonized. This can be seen in the numerous ‘intermedia’ and ‘school dramas’ of that days which have been preserved to this day in manuscripts written in the Latin alphabet."

The sentiment of the writer against Russianizing or Polandizing Belarusian is clear. I strongly disagree with this kind of sentiment (which is, unfortunately, present in other postcolonial countries). Much more important than keeping languages distinct from each other or "pure" is the responsibility of writers to reflect and to constitute what is going on in real life.