DADA's never-lasting teachers

[hp_fan16]

No: HPFGUIDX 43620

yes yes it's been talked about but i had to talk.

I've always been very curious about the DADA job. Some of the book's 
most memorable characters have held that position. But it seems that 
there must be some *good* reason no one can keep the job. All of the 
poor (I don't mean money wise) teachers left the job because Harry 
stumbled upon their secret incompetence (Quirrel and Lockhart) and 
they *had* to leave the job. And of course the better teacher's 
(Lupin and Crouch!Moody) had secrets as well that caused them to 
vacate their potions. The common denominator? Secrets! I have no clue 
what that's supposed to mean, or even if it means anything, but it's 
interesting, (to me at least.) 

So I'm thinking, is this all part of Dumbledor's great plan? Is it 
just a coincidence? Or a curse, or some spell to prevent Harry from 
learning too much? (unlikely as any may be) I just wonder about it.

An other thing I wonder about, pertain to DADA that is, is how come 
Dumbledore, who defeated the dark wizard Grindelwald, never taught 
DADA. He taught transfiguration, why? He knew so much about the dark 
arts. 
Again Snape is a character who follows this suit. He knows all about 
DADA but teaches potions! Perhaps, there really is no better potions 
teacher, but we also have yet to see a better DADA teacher (with 
potential to last) So can't he be the DADA teacher, and leave it some 
mediocre potions master to handle the class. Especially, with the 
Dark Lord back, you'd think they'd want the "best man" for the job. 
(true Real!Moony will be teaching next year but.. still) 

It seems to me as if, Hogwarts simply doesn't want students educated 
of the Dark Arts. It certainly appears to have been the way, even 
since Dumbledore taught Transfiguration. But, Why? Is there some 
deeper reason, or am I just asking way to many questions?

Gabrielle~
who must continuously refrain from arguing against herself~