bearisgray

It is rude for students to come unprepared for a class - ESPECIALLY if they have had access to the information of what they need to bring and what their skill levels should be.

Unprepared can be:

Not bringing required equipment and supplies
Being late
Having inadequate skills for this particular class
Not knowing how to USE the equipment

It takes time away from the other students to learn what they were hoping to learn while the instructor tries to bring the "student from wish-you-were-ready-for-this-class" up to speed.

If I've paid a lot of money for a particular specialized class, I want the instructor to spend most of his/her time on being able to teach the advertised content of the class. Not "how do I thread my machine?" if the course is on paper piecing, for example.

It makes as much sense for a beginner-beginner to sign up for advanced classes as someone taking remedial arithmetic/math to sign up for an advanced calculus class. (Except colleges make students take placement tests before allowing someone to take advanced classes)

A disclaimer:

IF the promotion is for a "Very beginner" class - then I would expect some basics such as the following would be covered:
1) This is a needle. Needles come in various sizes.
2) This is fabric. These are grainlines.
3) This is thread. It comes in various weights.
3a) This is how you "thread a needle" and make a knot in the thread
4) This is one model of a sewing machine. Separate classes are held for learning how to operate your particular model
5) This is cutting equipment. Then one could go on about scissors and rotary cutters.
6) These are measuring devices – rulers, etc. - how long an inch and a yard are (or meters and centimeters) - what is a FQ
and so on

Just as there are teachers/instructors that could be better, I am reasonably sure there are "students from h*ll" that make instructors vow to never teach again.

Another disclaimer:

Not all of us have all the tools/equipment needed for some activities. It's a fact of life. If one has to borrow or rent something, a class where others are prepared is not the time or place to try to learn how to operate it.

I do remember what it's like being a beginner-beginner. It's how I feel when trying to navigate this board.