Low-effort posting is a problem inherent to reddit. It's easy and quick to process and upvote a simple post; it's harder and slower to process and upvote a more complicated post. Thoughtful and substantive posts end up buried under a mountain of quick-draw, ankle-deep replies. Here are three ideas to encourage the former over the latter:

  1. "Discussion of the Week" awards. The process is simple. Each week the mods sticky a "Discussion of the Week" nomination thread to the top of the front page, and readers can use that space to link to high-quality discussions. More visibility for the best discussions, more eyeballs on the posters generating the best content.
  2. Remove posts that don't include a short paragraph of explanation. No more drive-by link dumping, no more open-ended "What do you think of this" posts. You're taking up space on the front page; put at least a few sentences of thought into the topic you're interested in. Offer an opinion on the issue, or at least highlight what parts of it you think are ripe for debate.
  3. Add a rule against low-effort posting and give mods discretion to remove low-effort comments. This is extending a milder version of the previous idea into the comment section. Allow users to report (and mods to remove) pithy or sarcastic one-line replies, and especially whole strings of them. It's possible to have a concise yet insightful comment, but the vast majority of one- or two-line replies are nothing more than dismissive and closed-minded. Part of having a discussion is actually considering what the other person has to say, not simply skimming over it and immediately telling them they're wrong. Detail why they're wrong. Or how they're misunderstanding your point. Or what specifically they're missing. To make this rule less subjective, it would only be applicable to comments of three sentences or fewer.

Giving greater recognition to high-quality discussion will encourage more of the same, and banning low-effort posts/occasionally removing low-effort comments will encourage users to put a bit more thought into what they're writing. No discussion will be hampered so long as they involve a modicum of effort.