If one machine had superier quaility on both build and cut, dispite it's looks, then it should always be considered.
Since several manufacturers spend a ton of money on R & D, many times several mowers are equivalent in both quality of build and cut.
Once you have equivalent mowers, it come down to marketing. As much as some of us do like like to see marketing sway the way people purchase mowers, it is often the only force that made a difference.
Marketing departments know that they can sway some purchase decisions based on the fact that if a mower looks modern to someone, then it might be a superier mower in that person's eyes and that will create additional sells.