Nothing more to say, Google already full of it.
Here is my list of why,
The cripple UI.
Stories that does not related to IT or "Nerds" anymore. If I want to read about politic or economy I will go to time.com.
Comment full of sh*t. The main thing that I like in old Slashdot time was their comments. They give you, at least, two sides of view that make you "hmm" and know others side of Nerds.
For you who seek for an alternative see Y. 
Also, I welcome reddit!