You could say the same of Marx who lived a very decadent lifestyle himself. Or Hobsbawm to declined an invitation to actually live in the USSR himself.
You're going to kill me. But for me There's a bit of Seneca in RMS. The guy makes it so hard to live by its principles that I sometimes wonder what is actual life is.
But to me, Seneca is not an issue. What he wrote reminds me of my humanity, encourages me on being a better me in the way it pleases me.
So, even after reading the long article, I still prefer the subjective picture I have of Seneca rather than his actual history. I'm human :-)