carb,
You will find the answer in here:
Why Is This Change Limited to B Nonimmigrants?
In the process of drafting this rule, the Service considered making its requirements (i.e., that nonimmigrants obtain a student visa before being able to take courses) apply to anyone in the United States not currently in student status. Such a requirement would be broader than the rule as presently drafted, which applies just to nonimmigrants in B-1 or B-2 visitor status.
B nonimmigrants generally enter the United States for purposes of tourism or for a business trip. Pursuing a course of study is inconsistent with these purposes, and thus inconsistent with B status. However, pursuit of studies generally is consistent with most other nonimmigrant statuses, and thus such a broader rule could have unintended and overly burdensome consequences for such nonimmigrants. For some, such a J-1 au pair or an H-3 trainee, the courses might be an integral part of the program for which they obtained their status. For many dependent spouses, such as H-4s, derivatives of A or G diplomats, or NAFTA TN-2s, studies may be their only permissible pursuit while accompanying their spouse who is working in the United States. Dependent children are, in fact, expected to attend school. Even some principals in nonimmigrant status (e.g., H-1Bs, L-1s) may take courses incident to status to enhance their professional development. Requiring that these individuals change to F-1 or M-1 status in order to pursue studies would eliminate their ability to attend part-time, since by statute F-1s and M-1s must be pursuing a full course of study and since a nonimmigrant is prohibited from holding more than one onimmigrant status while in the United States.
They did not list other Visas since on some Visas you are allowed to pursue studies. A Visa Waiver is just that, a waiver, it is not a Visa. You cannot change your status unless you are on a Visa.
On May 27, 2002 the New York Times printed an article titled, "Flight Schools See Downside to Crackdown"
In the article it is stated:
But under the new rules, schools and colleges cannot admit foreigners carrying tourist visas. A school that does so, including a small flight school, can lose its right to admit any foreign students, according to Russ Bergeron, a spokesman for the immigration service.
You cannot be granted entry to the U.S.A. for training without the proper Visa.
The Visa Waiver Program is explained in the U.S. Embassy Website:
Details about the Visa Waiver Program
Important reminder: Visa-free travel does not include those who plan to study, work or remain more than 90 days. Such travelers need visas. If a U.S. immigration officer believes that a visa-free traveler is going to study, work or stay longer than 90 days, the officer will refuse to admit the traveler.
I hope this clears up the situation for you.
Take Care,
Richard