On Snape, the Potions Master

(copied from my Facebook)
[I have been] thinking about how fortunate Hogwarts was to have Snape as potions master. I remember thinking when I was reading it that he was being a jerk for having then copy out potion directions all the time  or making them work from the board in a dark room often filled with  smoke and vapor; when, in actuality, it was because the book was  stupidly just a little off. I imagine Snape writing letters after each year with corrections and suggestions for the book and each year the publishers  ignoring his owls and saying to themselves, "not him again! Generations  of Hogwarts students have used our books with perfectly good results.  We're not changing anything because of that ex-Death Eater, even if Dumbledore thinks he's changed."
Still on the outside, no matter what he does.
And even though it's not fair to expect Hermione to recognize young Snape's  handwriting; because I know there's a big difference between writing for a class and writing a note for yourself; she should have recognized  his style and noticed that for 5 years he was giving them slightly  different potions directions from the book. I know that's a big leap from "Snape also used different directions" to "Snape wrote these directions;" but it's odd to think the thought never crossed her mind. Although the year of the book; and that he wasn't the first owner, was a distraction from that theory so maybe it's unfair to  blame her.