I frankly know only two people from different social and age extraction that do this, and they are just a bit above average in terms of success... in the end to think to spend money on something like that you need to have money to spend, so need to be at least a bit succesful, for merits or luck. 
I think the causality is the reverse of what someone would think: they are a bit succesful, want to be more succesful and are not so indipendent and not so smart; so they ended pay someone to talk banalities that for them probably arent banalities.
I would be curious to observe in the long term if they still will have success and how the courses will incide. My bet is that if they will continue take decisions with the same algorithm they used to decide to buy the courses, they probably will not continue to be so succesfull in the long run... 

 I add that obviously there are different cases, some gurus are so trash and most courses are scams for rich people, but I'm sure some of them could be useful. My critics is general about the industry that proliferated and my personal experience about it, in theory there's nothing more sane than pay some virtuous and good human to teach and explain you some new perspective about life.