That is to say, I believe people feel negative and positive and certain places and ideas can add or reduce these feelings.
I don't really believe graveyards have "negative energy" - I believe people view them negatively for a variety of reasons and thus feel negative whenever they come into contact with them.
When I was a tiny kid, we visited the shrine where my great grandparents' ashes were entombed (not in an urn, just in a nice little cozy buddhist garden) and I thought it was pretty awesome. My parents had brought me and my little cousins some candy, and we arranged part of the candy (eating the rest) in a cute little offering at the little patch of dirt set aside for our ancestors. The adults were a bit more solemn, but they laughed and smiled when they saw our handiwork and commented that they wished the great grandparents were still around to see what we did for them.
Looking back now I realize that was an Asian version of a graveyard; even so, there was no particular feeling of superstitious dread there.
So my personal perspective is that bad hollywood horror movies and other forms of pop culture are responsible for "negative energy" more than anything. It's a psychological, subjective effect, not an actual objective property.