Grammar Nazis

I'm recently reading the Canterbury Tales by Geoffrey Chaucer. The English is amazing in that work:

Whan that Aprille with his shoures sote
The droghte of Marche hath perced to the rote
And bathed every veyne in swich licour,
Of which vertu engendred is the flour;
Whan Zephirus eek with his sweete breeth
Inspired hath in every holt and heeth
The tendre croppes, and the yonge sonne
Hath in the Ram his halfe cours yronne,
And smale foweles maken melodye,
That slepen al the nyght with open eye-
So priketh hem Nature in hir corages;
Thanne longen folk to goon on pilgrimages
And palmeres for to seken straunge strondes
To ferne halwes, kowthe in sondry londes;

The moral satire in the general prologue is hilarious and it got me to thinking how much the words of language have changed over just 600 years in English but the ideas are still able to be comprehended. English is still changing. For Example, prepositions are now acceptable in a sentence to end with. The difference between less and fewer has been thrown out the window at most grocery stores. I think correcting grammar is very necessary when the words get in the way of conveying the ideas but when the rules get in the way of the ideas well enough alone should be left.