There are currently two posts on the non-meta site using the discussion tag, and I'm inclined to think it should be removed from both. By the site's FAQ, we state that we want to avoid questions which are purely about discussion with no potential for a complete answer. Further, couldn't every reasonably complex question receive this tag (rendering it entirely useless)?
I think that a discussion tag encourages bad behavior. I vote we get rid of it. In fact, I believe I will use my editing powers to do just that right now.
Links in case this gets down voted and we need to add them back:
You're absolutely right.
One of the distinguishing features of Stack Exchange is that it's a question & answer platform and discussions are prohibited on the sites.
We even have a "Not Constructive" close reason that addresses that (emphasis mine):
This question is not a good fit to our Q&A format. We expect answers to generally involve facts, references, or specific expertise; this question will likely solicit opinion, debate, arguments, polling, or extended discussion.
It is further covered by the FAQ section common to all Stack Exchange sites:
If your motivation for asking the question is “I would like to participate in a discussion about __”, then you should not be asking here.