But as interesting/correct as a lot of this post was it doesn't answer my question of why there were no Slytherins in school who saw a chance for power in being a part of Voldemort's downfall. I get that the forces at Hogwarts were basically the resistance but I didn't think Slytherins were about the status quo so much as favorable environments. So Voldy in charge helped the kids who wanted to be on the Dark Wizard path but that goes back to the problem of ALL the kids being like that without much justification. There wasn't one kid that was even a glimmer like Slughorn and thought they'd benefit more from the luxuries of a freer society?
"He's been stopped once so why not twice? Harry's an arrogant punk but if he wins this he's going to be popular beyond anyone else in the wizarding world. The Ministry's going to need a lot of new blood if Voldemort falls, and if I make a stand now and do well on my exams at the end of the year I'd be a shoo-in..."
It doesn't feel like it would have been difficult at all to slap in a character that thought like that.
It's funny though. As much as I get frustrated and pick at things like this I still really like the books and the setting they created.
Yeah, it was clearly a missed opportunity to do something interesting with Slytherin at the end of the series.
Slytherin does not equal Dark Wizard. Dark Wizard society exists in the Wizarding World, and is a significant part of the population. They've got areas openly dedicated to them like Nocturne Alley, and good people like Hagrid even shop there (although he warned it's not a place for good kids to hang out).
And Hogwarts/Slytherin House/the Sorting Hat aren't creating these Dark Wizards from nothing or turning good people evil (although they are providing a breeding ground). Snape was raised in a Muggle community and he became a Wizard Supremacist before he ever reached Hogwarts. Dumbledore (a Gryffindor!) was raised in a Wizard community and he was a Wizard Supremacist in his youth, with real plans to invade and conquer the Muggle world "for their own good".
Dark Wizards don't go to Hogwarts to learn the Dark Arts, they get sent there by their parents for the prestige of the green "S". The education they get there is secondary to social networking. Draco had been taught by his parents/private tutors to fly a broom before his first official flying lesson (although Snape joined Slytherin and emerged a Potions Master). Draco bemoaned that he would've preferred to join a
real school, one that teaches Dark Arts like Durmstrang, but his parents made him go to Hogwarts, because all the best members of Dark Wizard society take pride in their green "S".
And by being sent to Hogwarts, these kids have a real chance to change their fate, like Sirius Black who got sorted into Grffindor (and disowned by his family as a result), or by simply interacting with a wider variety of people, and learning to lose the hate. Is it truly wise to abolish Slytherin House (if such a thing was even politically possible, seeing how Lucius Malfoy was nearly able to have Dumbledore removed as headmaster, on an ordinary day), when the Dark Wizard society will simply move somewhere else? What would've happened to Sirius Black if he didn't meet James Potter and join Griffyndor, if his parents had signed him up to learn Dark Arts from Durmstrang? On the other hand, was Viktor Krum (the Durmstrang Champion) truly evil?
And Ron once said that all the Dark Wizards come through Slytherin, but Gellert Grindelwald (the big bad before Voldemort) was a Durmstrang washout.
Slytherin clearly doesn't equal Dark Wizard (it's more complicated than that), but the end of the series didn't do that idea any favors. And then Harry just turns around and tells his kid it's okay to become a Slytherin, because Snape was a Slytherin and he was a real stand-up guy. Real bros, those Slytherins. Will only occasionally argue unanimously in favor of handing your head to the Dark Lord on a plate. Two or three times, at most.