Oqlf as an advisory or educational institute to advise the government of what is correct terminology on official documents and to suggest 
new words or correct translations of things,  sure. 

As an agency that dictates,  fines,  monitors, and harasses PRIVATE businesses.  NOPE.

Freedom of commerce,  freedom of expression.  Freedom of choice. Yes.

There are a few truisms in business: "money talks" and "the customer is always right". 
If my customers are Korean speaking,  I'll have Korean on the menu and hire someone to speak to them in Korean.  

Separation of commerce and state. 
Keep businesses out of running governments and governments out of running businesses.