In sonnet 130, the speaker is making fun of the conventional poetry in Elizabethan England. The sonnets of that time followed the Petrarchan style, using beautiful metaphors to praise an idealised female lover, admiring her beauty and her worth.
I think that writing this sonnet, Shakespeare is mocking a style that had already become cliché at that time. Also, I share the speakers attitude in the way that the idealization of a love interest in such manner, often leads to the creation of beauty standards that are far from the truth and can have negative consequences in the people trying to adhere to them.