lostlogin posted some links to better stories, but the short of it is that the 50 hives were knocked over into the snow, which probably led to the tops falling off, etc. and the death of the bees. It's quite possible that there's not a huge amount of physical damage to the hives themselves unless they're large and heavy enough to have broken badly when they hit.

Technically, they're vandals. They vandalized someone else's property. The motive doesn't change that fact.

My other thought was it was someone stung by a bee in the area.

Envy, boredom, anger, signaling to others or showing off were good enough reasons for vandalism amongst many of the kids I went to school with. Financial gain wasn't a requirement for them to be destructive.