Like all organizations - the founders of the AMA probably held it to its noble cause - coordinating medical observations and results for best practices.
But, like all organizations (and even churches and nations), the leadership itself becomes a position of power rather than a mission statement and it becomes more important to protect the org than execute its stated goals.
This is when truth fails and “just do what I say because I’m wrapped in the organization and I know best” becomes the order of the day.
See also - Boy Scouts, Disney, current leaders of the “free world” and the current Pope.
The AMA like all organization was part of the ‘long march’ through the institutions. The Left has been working tirelessly for years to get control of organizations with influence. The AMA is just another on the list.