Dumbledore is a Dumble-dumbass
“I can't believe you actually planned that, you dimwit. How could you even attempt this? This is a school, they are here to learn, not to become your little soldiers,” yelled Snape as he stormed out into the hall, he then turned back around and walked back into the room, “this is MY classroom, GET OUT!!!”
The headmaster left the room, with his head held low, looking like a scorned dog, and the sole student in the hall looked into the class incredulously. She noticed that Snape seemed to be doing breathing practices at his desk. She had just decided to walk away when he looked up and noticed her trying to slowly escape.
“Please come here Ms. Granger,” he beckoned.
“Yes professor,” was her only answer.
“Listen, I’m going to talk to you first, then I'm going to set up a meeting with the rest of the whole student body apparently.”
“What is it professor?”
“What Albus is doing is wrong. I need you to understand that it is not your job, nor Mr. Potter’s job, nor any other student's job to fight he-who-shall-not-be-named. It should never have even been thought of that way, no kid should have to fight in a war.” said Snape as his anger rose again.
“But-”
“No. There is no but in this situation. You are a child, not a soldier, not even a fully fledged witch yet. You should be learning about how to brew spells, not how to fight in a war that shouldn’t have ever included you anyway.” He said, urging her to understand what he's trying to get across.