Neither. I think that they are great for people who cannot handle the heat in the summer, or for those who burn very easily. For me personally though, they would be all for decoration, as I am used to being in the heat and sunlight. I think they are a cute accessory and functional to most, especially if they can also double for an umbrella in case of summer showers.
I do not have any parasols yet, but I definitely want a couple.