Nobody can agree what makes a good MLP. Submit a short one and many people demand a better write-up. Give a detailed write-up and they say "This should be a regular story. -1, rewrite slightly, resubmit in section X and I'll vote for it". These voices often win, meaning the same story can go through several rewrites before ending up somewhere - often not in MLP.
If everybody felt that way, it wouldn't be so bad. But there are obviously also plenty who like short and plain MLPs. Mix together them, the people who vote down MLPs because they don't like them and those who vote them down so they can be resubmitted (maybe elsewhere) and you have a recipe for a long stay in the queue.
While other stories may get stuck in the queue, it's usually for different reasons. Whatever else we may disagree about, most people here agree that a regular story should be well written-up and provide meat for discussion. The result is that most regular submissions go in - or drop out - faster.
So scrap the MLP section. End of a source of needless conflict. It's been far easier for us to reach consensus on the mimimum quality needed for a regular story than it is to agree on what makes a good MLP. If something has been written up well and well attract good discussion, it should go to a proper section. What is this doing in MLP? It should be in Culture. Good story, too.
If you can't think of something thought-provoking and interesting to write about a link you're submitting, stop. Don't submit it. This is a discussion site. Why should we take anything and everything? There's several other sites that do that just fine. It's the quality of the discussion that's supposed to count here. If you want random noise to soothe your brain, Enterfornone knows just the place.
If this means fewer stories are submitted - GREAT. Let's buck the trend of the century and do less with more care.
The clear thinkers among you will realise that there's another possible reason why there are so many MLPs in the queue: maybe more MLPs are being submitted than any other kind of story. Even more reason to drop the section: if we're getting more MLPs than anything else, we're losing focus.
Time to cut the crap and get back to what we do well.