It's not about the quality of the content on sites like grouphug.us, but the nature of the content - things that the poster might be happy to be forgotten in 20 years time.
Previous generations youthful indiscretions tended not to be preserved for all time, for the most part.
Even better. All the stupid stuff you did on the Internet that you've forgotten that you did. There are no doubt numerous examples that could come to haunt me in later years. Stuff I don't even remember.
Part of the problem with putting your thoughts down in writing is that if you change your mind later the writing is still there. I think that in the years to come were going to see more scandals arise from this sort of thing.
Previous generations youthful indiscretions tended not to be preserved for all time, for the most part.