Skylights are a double-edged sword.
They basically ensure that you will be woken up by the glaring sun earlier than you'd like to be.
On the plus side, they look cool and sometimes a cat will sit on them.
It is much better for a cat to be sitting on your skylight than biting your feet, jumping on your feet, scratching at your feet, etc. They like feet.
Also, sometimes they try to prevent you from leaving the bathroom by pushing the door closed when you're trying to get out. Cats are surprisingly strong.