Probably having a different opinion than @Bluedwains, but I like sugar. It is very energy dense and I am very explosive, so I need all I can get. It is healthy if you make use of it, not if you just eat a lot of sugar and then go sit on the couch.
But there are some cons yes. It breaks your teeth of like crazy, so your chances of loosing teeth increases. Also the fact that the body breaks it down slower than healthy sugars is a con. So you really need to make heavy use of it if you don't want the problems sugar comes with.