I'm not exactly sure why contacts would cause more harm than good, unless you sleep in them. I personally haven't worn them, but it seems like they help people see without having the annoyance of glasses. So even if they cause dry eye, it's still better than having expensive, annoying glasses.
I've never been under the impression that contacts hurt you in any way more so than glasses. To be fair there is an argument that glasses are essentially damning as well by constantly refocusing your eyes and putting extra strain on them instead of making them better only moving you into stronger scripts so I'm not sure.
With special care and consideration, contacts are a freeing tool for those who wear glasses. As long as people ensure cleanliness and care with use, they can be comfortable and used in situations where glasses are not appropriate. They are a great alternative for those who wear glasses and want another option.
I have never heard of contacts causing harm. I know they can cause eye's to become irritated, however if used properly, they rarely do that. I think overall, people are satisfied that eye contacts exist, and that they do more good than they do harm. Some poeple don't like glasses, so contacts are ideal.