I do not think all consultants are scammers, but a lot of them have given the titles “podcast consultant” and “mastermind group” a bad reputation. The concept of the “mastermind” (or more correctly termed “Master Mind”) came from Napoleon Hill in the classic book “Think and Grow Rich”. The concept is simple: surround yourself with knowledgeable experts in the field with the purpose of collaboration “in a spirit of harmony” (to quote Hill) to create one “Master Mind” of knowledge, because knowledge is power.
Nowhere in the book does it say anything about “buying into” a Master Mind. This is purely an invention of those who have essentially exploited the original concept and bastardized it into a money making scheme in and of itself.