exemptions to govt co. from limit of max 15 directors and thier increase in limit

As per the notification G. S. R. 463(E) dated 5th june 2015 the limit ofax 15 directors and their increase in limit is not applicable to govt. Co..
And as per notification dated 13th june 2017, the same clause is not applicable to sec 8 co.
I wanted to know the logic behind the same. What is the reason for exempting them.?