Having a single official language brings society to the conclusion that whatever language which had been chosen is the best or in other words more important, and makes it a must for all citizens in the country to adopt the language even though it isn’t their own. It makes other language speakers feel inferior and have no interest to work with official language speakers. Having a single official language also brings difficulty in communication.
In some cases, having a single official language may bring about ethnocentrism which results in unwanted conflict to make the country less United