Derogatory as in detracting from the value of the original.
“Amateur tosh” was the comment I referred to. I’d wager that everyone here is an amateur writer so it’s not particularly helpful to point that out and ‘tosh’ is a fairly poor description.
And these prequels/sequels detract from the original because it was a moderately thoughtful piece of writing and these are almost completely unrelated.
I did like “man-muster” though. I’ll give you that.