I've made it a little bit into that one Martin Scorsese article, and needless to say, it's getting me REALLY fired up. In fact, it's helping me to tap into my serious ethos as a critic (instead of the half joking one I have pinned up on my profile).
To expound a little on this: when looking at the problems that plague whatever context it is we're focusing on in a given moment - art, society, politics, etc. - it can become all too tempting to retreat into a much simpler vision of the past: back when things were better, when people were people, when we could just enjoy things without having to worry about whatever complex burdens weigh the present day down. The ease with which this attitude lends itself to a reactionary politic has been obvious to everyone for, well, centuries now, but as a critic my ethos, my impulse is to challenge these conceptions of past and present from within the past itself. Look not only at the forgotten parts of the past (these can too easily be rehabilitated as hidden gems; visions of the past made productive within the present moment), but the parts that were never committed to memory in the first place, since those often have so much more to tell us about that past than the successes we take for granted. Undermine the desire to retreat into the past by demonstrating how bound up it is in the present it necessarily led to and which we desire an escape from. In short, unsettle nostalgia with a positively ruthless historicism.
And just to give myself something to end this blurb on, some historians and critics I would recommend in light of what I just said:
(There are definitely a few others I want to recommend, but I can't remember them off the top of my head right now.)