AM has good points and bad points. Some of the criticisms have been "explained away" but such explanations were based on faulty assumptions. I have been dancing now for more than 10 years, and my first year was with AM.
First, they do have a lot of inexperienced instructors. 6 weeks or even 3 months is not even close to being sufficient experience to teach several dances. It is important not only to be able to know the basics of the steps you are teaching a beginning student, but you must also be showing by example the technique that will be needed to dance properly at a more advanced level. Also, you NEED an understanding of the more advanced level to understand the intent and direction of that underlying foundation.
That said, AM also has very good and experienced instructors.
It has been said that Am "holds you back" from advancing. The argument against this is that you must first learn the fundamentals before you are ready to learn more. While the latter is true, that does not mean the former does not also occur. Some students are simply faster than others. I am fortunate that I have always been a fast student. I was frequently stymied in my learning during that first year, not because I was missing knowledge, but because the instructor was not yet allowed to teach me something. Or, couldn't teach it because she hadn't learned it yet herself. Looking at who was "advanced" to the next level and who was not, advancement seemed to be much more about how long you had been taking lessons and how much you had spent rather than about what skill you had developed.
It has been said that AM is very expensive. That is relative. If you are able to attend a lot of group classes every week, which are typically free as long as you are taking private lessons, the cost then becomes comparable to what you would pay for the same number of privates and group lessons at an independent studio. If you are not able to attend many group classes, then AM is more expensive. So it really depends ion your availability to take full advantage of what is there.
During that first year, each week I took 1 private lesson and typically attended about 5 group classes and a couple short parties. Could I have saved money by doing that at a private studio? Probably, but not much. But the bottom line is that it is questionable as to whether I would have learned as much at a private studio. That may seem paradoxical since I said they also held me back a little. But AM is very syllabus driven (and they have a good syllabus). That means that students actually get through the syllabus. Getting through the syllabus is more restrictive in some ways, but more thorough in others. Do I think that someone on Bronze II should be refused instruction for a figure in Bronze III or IV if they are excited to learn it? No. Do I think they should have a strong foundation in Bronze to learn a Silver figure? Yes. But then I also think the instructor should have a solid foundation in Silver to teach Bronze.
I also think that AM instructors should be a little less flirty inside the studio, and a little more friendly outside the studio. (The non-fraternization outside the studio clause is ridiculous for those who can be professional adults.)
All in all, the good with the bad, I really can't complain that my AM experience didn't give me what I needed. I am a perfectionist and I drive myself hard, and in the end that didn't fit with the culture and I moved on.
Anywhere you go, you will find good people and bad people. In any work place you will find competence and incompetence, professionalism and unprofessionalism. Welcome to planet Earth.
Meanwhile, find the studio and instructor that fits best with you and your needs, and keep dancing... lead/follow with your frame, practice your technique, and have fun!