That article from Mamet is two years old and pretty incoherent. Looks like the ramblings of as well-off sell out to me. As that commentator says:

‘…he [Mamet] is “hard-pressed to see an instance where the intervention of the government [has] led to much beyond sorrow,â€? and nowhere in that essay or the pages of Theatre does he betray any interest in the social issues that are central to the belief systems of most conservatives.’

Critics also now reckon his best plays are behind him (and surely his best one was Glengarry Glen Ross, in which as Michael Billington says, ‘he depicts the way a group of salesmen are demeaned by a cruelly competitive, capitalist ethic’.