Why palm trees get a haircut?

I love unkempt palm trees and never understood why people insist on this intrusion into the life of a tree. Recently I found out that the reason is that rats and raccoons live in those crazy trees and I loved it. Though now I think twice before I park myself to sketch under one of them :)

I saw a group of people singing while trimming palm trees once. They were working in harnesses, using large machete knives and were laughing and keeping the rhythm of the song with their work. I hope all of the palm trees are getting a haircut with songs and laughter.