I think sugar is a more apt analogy than smoking. Facebook, like sugars, provides a source of a required human input. (Calories/human connection). Overdone, both are harmful.
Tobacco is a much more charged analogy, and is more extreme in terms of positive/negative balance. I think it reveals more about the biases of the person making the statement than it does about social media.
Sure, candy technically has calories. But the fact that human beings need calories isn't a good argument for eating candy. You can also get calories from healthy foods, and you can get "human connection" from, you know, talking to people, or sending text messages, or reading reputable news sources. Not coincidentally, the idea of a "social connection" was and is also a big part of apologizing for smoking as a habit.
That's also true of just about anything humans can consume. For example, sugar.
But, I dont consume much news from facebook (outside of reputable sources, like NPR), nor do I pay much attention to it in general, and I'm VERY cautious about what I post, to avoid anything that could create controversy or waves of any sort.
At least Facebook actually provides something of value to the hundreds of millions people who use it.