Park,
Yes, I'd say it is wrong to not offer form classes. As in all things "educational" you must tailor the level of information to your audience. A 6 or 7 year old will take 2 or 3 classes just to get the arrow on the string. Older students will progress at a faster rate -- usually. I do a lot of this and generally try to get the form mixed in with making sure the students are having fun too.
All form can be deadly boring to a kid and all targets will be counterproductive too(they'll see little to no progress). There is a learning curve for instructors too. If you aren't already a basic or intermediate instructor , try to get that training. You'll get many good ideas for your own classes.
Good on you for doing this, you will find it fun and rewarding!