Positivity and its role in education

When people ask me whether I see the glass as half empty or half full, I am prone to believe that either way, I'll need a refill. In my reading skills class, we are using Tom Rath's How Full is Your Bucket? for our reading selections. The first topic was "Studying Positivity," or the introduction to why he wrote the book. The basic premise of the book revolves around the Theory of the Dipper and the Bucket:

Each of us also has an invisible dipper. When we use that dipper to fill other people's buckets -- by saying or doing things to increase their positive emotions -- we also fill our own bucket. But when we use that dipper to dip from others' buckets -- by saying or doing things that decrease their positive emotions -- we diminish ourselves.

For me, the question I am wrestling with the most is How can a school's attitude change?

My family is currently visiting the Seattle area for my wife's cousin's wedding. Today we took some time to visit with the school I taught at before moving to Connecticut. Walking onto campus immediately brought positive vibes. The campus was clean even while students mingled outside during their lunch period. Snappy posters, probably created and painted by the leadership class, directed students and visitors. The students were interacting appropriately and pleasantly--a far different atmosphere than my current school in Connecticut.
I don't know how different the lives of my students in Connecticut are from my former students in Washington. In both places I have had to be concerned for students whose home lives were nothing but hell. So what is the difference maker?
Are my current students simply people who see the glass as half empty? Or maybe it has something to do with us, the teachers. It is hard to enjoy teaching in a building that is run down and lacking resources. It is hard to enjoy teaching in a building where students get away with treating you with disdain. I'll give an example:
As I walked through the hallway the bell rings to signal the start of class. I'm on my prep and wanting to stop into the library. A group of students continued to mingle by the steps so I give them a friendly, "Okay guys, let's head to your classes. Do you all know where you need to be?" The question is pertinent because we still have many schedules that are not correct. One young lady tells me to "Chill, Mister."
"I'm pretty relaxed; but we have too many kids in the hall, so let's get moving." I happen to be walking in the direction she takes off in.
"Why you followin' me? That's fucked up. You better back off me." She takes off ahead of me; I'm not interested in chasing her through the halls.
So where did it go wrong? I took the positive approach from the beginning, not yelling at them to get to class, just asking them to find one. She flips out.
I have to believe that much of it comes from a preconceived idea that we the teachers are negative, that our main goal is to make their life hell. And truthfully, I have seen many of my colleagues escalate situations by reacting far harsher than was necessary or prudent.
Which brings me back to my question: how can a school's attitude change?