What are the demerits of binomial nomenclature?

Ans : The demerits of this naming system are as follows:

• If two or more names are in actual usage according to the priority rule, proper names will take place first and the other names will be treated as synonyms. This is because authenticity, reliability and accuracy are synonymous with the senior. 
• The names whose use takes place by Linnaeus before those included in the “Systema Naturae” are not given recognition.