Snape's Reaction to Harry assuming that he is a DE spy

[Casey]

No: HPFGUIDX 108507

Vmonte:
This scene has always bothered me. It is interesting that Snape 
tells Harry that he is "neither special nor important." I mean what 
a drag it must be for Snape to have to work with Harry if he really 
feels that he is a nobody and not important. 

Casey: 
I always took it as punishment for Harry's father. James was always 
special in school, i.e. popular, athletic and handsome, three things 
Snape wasn't. Now here comes his son, who by his very existence, was 
a hero, it had to irk. Snape hated "special" James and he sees Harry 
being set up to be just the same. And we all know how James handled 
his status.

 Jen: 
It makes me re-think why he specifically singles out Harry & 
Neville. Maybe Snape was somehow involved in their parents death, 
and Harry & Neville are his failures staring him in the face. Or he 
was orphaned like them, and despises them for being like him, 
instead of feeling empathy. Or it is just simply him trying to put 
them in their place, keep them from getting big heads (lol, Neville 
with the big ego). 

Casey: 
I'm mixed on my feelings on this issue. I thought Snape punished 
Neville for just the opposite reasons than Harry. We've never heard 
anything bad about them, even in dealings with Snape (if there were 
any). Heroes in the war, injured in the line of duty, their son is 
turning out to be a huge disappointment. Barely above squib (when 
the books start) and accident prone, he's a far cry from what his 
parents deserved. Snape isn't a nice man and seeing this boy doesn't 
make him pity him, instead it makes him hate him for his weaknesses 
on the Longbottom's behalf.

Then again, he's cruel to Hermione when given the chance so, it may 
be something as simple as Neville gives Snape more opportunity to 
show his bad side.