What happened to the negativity argument?

One of the comment arguments against atheism, or against the atheism as a social movement, is that it's too "negative".  There are a variety of arguments in this category, ranging from the respectable to the absurd.  It can mean, "If you destroy religion, what will you replace it with?" or "You can't base a whole movement around something you oppose," or "Stop being so critical!"  The general attitude is so pervasive that I tried to rebut it seven years ago, immediately after I started blogging. 

At the time, I was simply expressing the dominant opinion among atheists, which was that the negativity argument was entirely wrong.  Interestingly, it is no longer the dominant opinion!  In my view, the negativity argument was victim to the same social forces as the tone argument.  Since 2011, a lot of atheists finally realized they have some rather severe disagreements with each other over feminism.  This led to a crisis, since for many people, the negative definition of atheism simply wasn't working.

For example, in 2011, PZ Myers defined and criticized "dictionary atheism":

Dictionary Atheists. Boy, I really do hate these guys. You’ve got a discussion going, talking about why you’re an atheist, or what atheism should mean to the community, or some such topic that is dealing with our ideas and society, and some smug wanker comes along and announces that “Atheism means you lack a belief in gods. Nothing more. Quit trying to add meaning to the term.” As if atheism can only be some platonic ideal floating in virtual space with no connections to anything else; as if atheists are people who have attained a zen-like ideal, their minds a void, containing nothing but atheism, which itself is nothing. Dumbasses.

A year later, Jen McCreight proposed the idea of "Atheism Plus":

We are...

• Atheists plus we care about social justice,
• Atheists plus we support women’s rights,
• Atheists plus we protest racism,
• Atheists plus we fight homophobia and transphobia,
• Atheists plus we use critical thinking and skepticism.

Atheism Plus is essentially a response to dictionary atheism.  If you say, "Atheism means only a lack of belief in gods," then I can say, "True, which is why 'atheism' isn't sufficient to define my goals."

Even though Atheism Plus didn't really go anywhere, these ideas continue to be repeated today.  For instance, a more recent article on Pharyngula said:

Movement atheism, as currently formulated, has serious problems precisely because it refuses to incorporate any position on human values at all. It’s in the awkward state of trying to be all things to all people, a blank slate on which Libertarian atheists can scribble selfish manifestos, or Humanist atheists can state their altruistic values. I’ve been arguing not that atheism leads inevitably to liberalism, but that if we don’t make any commitment at all to any progressive ideas, we’re only going to descend into chaos and purposelessness.

Each of these three quotes offers a successively stronger variation on the negativity argument.  First, PZ points out that atheists as individuals do in fact have "positive" views and goals that we should acknowledge.  Then, Jen McCreight expresses a desire for a movement that includes some of these positive goals.  Finally, PZ says that without well-defined positive goals, the movement is chaotic and meaningless.

This is a simplification of the progression of ideas, but it's suitable enough to seed discussion.  The history of the negativity argument raises several questions:

1. Which forms of the negativity argument are correct or incorrect, and why?
2. Why was there a change in the way people view the negativity argument?
3. By what process was there a change?  Is this a matter of people changing their minds, or of people leaving and entering the relevant group?