My wife and I met online ten years ago. At the time I was looking for information about travelling in the US I was in England.. So it was not with the intent of looking for romance. In the end the romance came.
I do think long distance relationships can work out. It just takes time and effort.
A relationship has to start somewhere, online is just another place to make initial meetings, it is little different from meeting someone through a dating agency or a blind date set up by friends.
I would not say it is a bad place to meet people, just that one needs to be careful. As in all situations one needs to prepare for bad things to happen, they almost certainly will at some point. Not neccesarily meeting an axe murderer, but meeting someone who makes you uncomfortable one needs to take things carefully at first and not to get carried away with a new relationship, again though, that is just as likely to happen in a more "traditional" meeting at the start of a relationship.