I agree that they can distract from the visual beauty of the tee, but there has to be an alternative. I am an AVID walker. I only ride during corp. outings and I will rarely if ever return to a course which requires a cart.
I know, cart golfers think walkers slow the pace. This is not the case when a path is provided that allows a walker to walk the course not the cart path. Not only are the cart paths usually a more roundabout way to walk forward, they do not allow a walker to view the fairway in front of him as he moves.
The two main reasons I walk are 1) for the excercise, 2) to get a better feel for the hole and to smooth the pace of my round.
The path does not have to be straight down the center of the tee boxes, but there should be access to a path.