I have seen it time and again. And I am at a loss to understand why people insist on jeopardizing the opportunity to try something new, enjoy the experience, and learn from it.
Think you know better than your instructor? Maybe you do, but why not try it her way first, in a low risk environment and where you can get help and feedback. At the end of it all, if you still think your way is the better one, then fine. It's still a learning experience.
If you are going to deviate from the instructions, be prepared for the consequences. Don't expect the instructor to take the time to get you out of the mess you created for yourself. That instructor has many other students (who did as asked) to deliver a lesson to in a limited amount of time. Be prepared to become an observer and take notes. It is a humbling experience, so be gracious about it. Complaining, whining, moodiness and disruption are unfair to everyone. Leave the classroom to compose yourself if you must.