In my critique of "The General Prologue," all I can see are the many positives.
Chaucer changed the course of the English language when he wrote The Canterbury Tales: he used Middle English which was something of a trend-setter. The ruling class had come from Normandy, France, in 1066 with William the Conqueror. Because they spoke French, there was a "great divide" between the conquerors and the conquered. The peasant class spoke Old English, and Middle English was just beginning to emerge into the society as was a new middle class. The nobility had had to make some adjustments regarding language because while they spoke French, their servants and merchants, etc., did not. However, when Chaucer chose Middle English, this seemed to pull all classes into a new linguistic era.
With regard to "The General Prologue," it is important once again to look to Chaucer, not regarding language now, but in terms of his position within English society. He did very well in service to the aristocracy, but in carrying out his duties for the nobility, he also interacted with the lower strata of society. It was his ability to move back and forth easily between the different social classes that enabled Chaucer to include characters from all walks of life, to intermingle as they would under no other circumstances: only a pilgrimage would bring the humble into the same "room" with the well-to-do and powerful—and a great deal of this power was represented by members of the Roman Catholic Church.
Chaucer was also known as a "student of human nature." He was very observant, and in his writing, he was very honest. With the emerging middle class, more and more people were being educated and could read, where before only the nobility and members of the Church were educated to read.
In the prologue, Chaucer is brilliant in using the pilgrimage as the structure that frames the story out and brings these people together. He presents characters that are very realistic. He not only describes them, but gives each character a tale to tell that Chaucer cleverly uses to divulge more insight into the character telling the story.
For example, the Wife of Bath is looking for another husband (she has had several), but she is not a good-looking woman, though she is wealthy. The inference is that she has a healthy libido, which may have caused the deaths of her husbands. As a successful business woman, she would be quite a catch, and she hopes she will meet her next husband on this trip. Her tale is about one of King Arthur's knights; to escape death for raping a woman, he must find out "what it is that every woman wants." The only woman who can tell him is an ugly old hag. She will tell him, but he must marry her. He agrees, but cannot stand the thought of living (and sleeping) with this crone. All of a sudden, she becomes a beautiful young lady: for what a woman wants is her way in all things with her man. When the knight agrees to this, she remains beautiful for him.
The Wife of Bath's tale reflects that one should not judge a book by its cover, and supports her argument that men should give her a chance.
Being written in iambic pentameter—in rhyming couplets—adds a charming rhythm to the telling of the story. Chaucer's genius in addressing all of these aspects in presenting his tale, as well as his rich descriptions of characters from all walks of life, make "The General Prologue" to The Canterbury Tales, a masterpiece that people still enjoy today.