Because I don't want anymore holes in the deck than I have to. And I like to be able to move around while anchoring.
I use a very inexpensive two channel key fob remote. The receiver for the key fob closes relays that controls the solenoid for the windlass. As a backup I have wired remotes with watertight connectors at the bow and at the helm. I have almost never used the backup. With the fob hanging around my neck I can be anywhere on the boat.
To lower the anchor I often start dropping from the helm. I can continue to deploy chain as I walk forward to read the length markers.
When raising the chain I can run the deck wash pump and direct the water where it is needed.