Partly a few of them have something about them which makes them seen unwell and thus potential lawsuits in the making. (Pecans are known as "self-pruning".) Partly they have decided to spruce up the bathing areas and expand them. Partly just don't want any branches overhanging areas where people are.

Several local tree people think less than ten of them should be cut down or heavily pruned -- and as you can see, no mulch has been added for years. They should dump a bunch of Dillo Dirt down there and see how much happier those trees will be. Plus...they haven't mentioned it, but the drought is hurting some of those trees. I got mildly hysterical back in July and shot out tree instructions to the neighborhood. It may take a year or two, but I fully expect the Montezuma Cypress in the area to die. They just didn't get enough when they needed it.