In what way?
The dumbing-down part is in relation to the rampant spread of misinformation/fear-mongering at the click of a button (KONY, et al) and the he-said she-said drama that goes on and is exaggerated by outside commenters who wouldn't have otherwise been a part of the dirty laundry.
(Reducing the effort involved in writing and publishing means that more trivial things are written about and widely distributed. You used to think that your friends weren't morons because they never said anything. But now that they can discuss any issue at any time, they don't come out looking so good.)
You forget that there's this huge network of people, people that could be your next employer or co-worker, future partner, that are attached to these otherwise meaningless comments you wrote just to be clever. I said to Jimbob was going to resurface down the road or that I'd end up in a screenshot posted on some site by anyone else that could have seen that conversation, even if it wasn't insulting to me personally.
Ultimately, I wasn't comfortable with my every day conversations being available to hundreds if not thousands of people that don't know me or my tone.