Let's try a simple statement to start:
Interacting on a lower level allows more people to stay coordinated than interacting on a higher level.
Imagine a group of 100 people looking at a screen. In the first scenario, the screen displays only two commands, 'left', and 'right'. With just a little practice, all 100 people can move in unison according to the commands displayed on the screen.
In the second scenario, the screen displays more numerous and complicated commands such as 'open a can of soda', 'do a jumping jack', 'draw a circle', etc. It is much harder to get everyone to do these things in unison, as they are more complex.
If we are talking about grass roots movements, it is very easy to get people to repeat simple commands, keyphrases, or behaviors. It is very difficult to get them to repeat actual thought patterns. Thus I would argue that it is much easier to build a stable grass roots movement with people that do not think for themselves than with those that do.
There are many historical examples of this phenomenon from the mother of all grass roots movements: religion. How many sects of Christianity are practiced in the United States today? I don't know myself, but it must close to a hundred. Christianity used to be one solid grass roots movement, but each time a sufficient number of free thinkers existed, a new sect split off. Christianity itself was a sect of Judaism started by a free thinker named Jesus and his free thinking disciples (sorry, I don't know their names). So to that extent, movements will be more stable if their members think less.
While I can't deny that there are many people who selfishly feed off of these movements, I attribute that more to the quality of the person and less to the means they use. There are ways to profit off of interactions with the masses while still doing a lot of good. Bill Gates raked in a ton of cash, but he distributed modern technology to every level of society, creating a much more advanced culture. Edison did something similar with the lightbulb. My point is that there is nothing wrong with taking money, but I agree that there is a potential for abuse.
I agree that following is a choice. I would argue that leading and even deciding to neither lead nor follow are also both choices. Now different people see these choices in different ways, and I can't really offer anything except my own personal opinion: all choices have their merits, there are no wrong choices among the three.