A reason for the success of the initial SIMS/SRM programs is the same reason for why such a "Movement" can't hold a candle against the fundamentalist and Monotheistic religions: namely, the latter are held together by a strong belief system, and faith in the certititude of Biblical truths. These conditions coupled with a strong cultural foundation and various social links spell for enclaves of Fundies in certain areas. For example, Shias in some areas vs the Sunni group, each with temples, social welfare projects, ....etc; the whole system of cultural traits which act as a "glue" to keep society together.
Same with Fundamentalist Christianity. In many areas across the US, with a couple dozen square miles of territory, especially rural towns, you can find hundreds and thousands of Fundies. The combined influence of these fundamentalist groups far outshadows (in number), the total historical influence of the TM groups. Thus, the freedom of belief systems and a strong relative focal point acted in the "early" years - (1959 - 1975) to attract a relatively large group of "New-Age"-type people into the fold (probably a wave of people with past incarnations in India); but this in turn over the years detracted from any sense of cohesiveness along the lines of the Fundamentalist groups who point to "Biblical truths" and strong cultural affiliations. In practical terms (for example); after Katrina the FEMA efforts turned out to be a total failure; with the most benefits to local areas coming from (you guessed it!) - local Fundamentalist Churches. The Dalai Lama appeared on CNN calling for a compassionate outlook. That's about it from the "Dharmic" Hindus and Buddhists (those with a past in that orientation who have gravitated toward TM).. No TM'ers rebuilding homes and clearing out the trash. OTOH, one can argue that the TM perspective will win out in the long run - hundreds of years into the future, because the belief systems holding the Fundies together are in essence (imo) much superstititious nonsense. From our TM perspective, as MMY has taught, the Foundation has to be "Being", ultimately; although this lesson in the short run will be lost on those attempting to clear up the Katrina trash, cure malaria, or offset the dwindling water supply in India.