I was looking for a biography of Marcus. Having been somewhat burned by reading biographies of historical figures that I later learned didn't have the best scholarly reputation, I was looking at reviews of the various biographies of Marcus. I stumbled upon a review by Mary Beard that contained the following passage:

But we have plenty of evidence that other Roman emperors were thoroughly philosophically trained: Hadrian, for example, or even the first emperor Augustus, who wrote his own Exhortations to Philosophy, now lost. There seems to me a fair chance that, though the Meditations is a rare survival, works like it might well have been found on the desk (and from the pen) of many a Roman ruler. What, after all, would Augustus’ Exhortations have looked like, if that had survived? And what difference would it make to how we told the story of his reign? To put this another way: might we not get further in understanding Marcus Aurelius and his reign by not treating him as a rare hybrid? With his desire for military glory, his disastrous succession plans, his wayward wife, and his spare-time interest in philosophy, might he not actually be rather ordinary by the standard of Roman emperors?

This obviously inspired my question. Do we make too much of Marcus's philosophical interests? Are the Meditations just a rare survival of a relative abundance of philosophical output by Roman emperors? If so, might they have survived because they were especially "good" or out of respect for Marcus himself? This latter option seems weird to me, given the high esteem Trajan and Augustus were held by latter generations.