Stoicism is not meant for slaves. One of the most prominent writers on Stoicism was literally the Emperor of Rome.<p>Another prominent writer inspired by the Stoics was Boethius, a prominent official who was executed for treason. He wrote The Consolation of Philosophy as a way to comfort himself while in prison. That is the target for much of Stoicism: the people with a lot to lose.<p>The name is derived from the Stoa, public places where people could gather to listen and discuss. That did make it more accessible than the academies, but still aimed at people with the time and liberty to be there -- not slaves.<p>The current fad for Stoicism is a pretty bastardized version of it. Which is well in keeping with long tradition, where every philosophy X gives rise to a neo-X a few centuries later, updated to the modern conditions, and then a neo-neo-X after that. Marcus Aurelius and Epictetus wouldn't recognize it.<p>The the author shouldn't get snooty about it if he doesn't know anything about it, either.
I think it has to do with people struggling to find meaning in the absence of inherited religion or any other guiding philosophy. The forces of capitalism and democracy have stripped away many communal traditions, but people still have a need for some kind of meaning, so it's not surprising they might turn to a philosophy that is highly individualistic and doesn't require an organized church.