1. A significant number of postings don't argue towards a discernible point.

2. A significant number of postings don't argue their point cogently.

3. Lack of awareness of standard counterarguments, and alternative theories.

4. Lack of appropriate response to objections.

None of this has anything to do with which answers are right or wrong. It is a form of the fallacy of grey to argue that since no philosophy comes up with definite answers, then it's all equally a failure. Philosophy isn't trying to be science, so it isn't broken science.

1. A quick way of confirming this point might be to attempt to summarize the Less Wrong theory of ethics.

2. Particularly the ones written as dialogues. I share Massimo Pigliuccis frustration

"I am very sympathetic both to Bayesian analysis (I have used it in my own research) and to its implications for philosophy of science (though there are some interesting objections that can be raised to it as a model of science tout court — see for example the chapter in Bayesianism here). Which is why the title of Yudkowsky’s column surprised the hell out of me! Alas, as I said, he provides no argument in that post for his suggestion that Bayesianism favors a many-worlds interpretation of quantum mechanics, or for the further claim that somehow this goes against scientific practice because the currently favored interpretation is the Copenhagen one. But then I noticed that the post was a follow up to two more, one entitled “If many-worlds had come first,” the other “The failures of Eld science.” Oh crap, now I had to go back and read those before figuring out what Yudkowsky was up to. (And before you ask, yes, those posts too linked to previous ones, but by then I had had enough.) Except that that didn’t help either. Both posts are rather bizarre, if somewhat amusing, fictional dialogues, one of which doesn’t even mention the word “Bayes” (the other refers to it tangentially a couple of times), and that certainly constitute no sustained argument at all. (Indeed, “The failures of Eld science” sounds a lot like the sort of narrative you find in Atlas Shrugged, and you know that’s not a compliment coming from me.)"

3 and 4. There's an example here. A poster makes a very pertinent objection tithe main post. No one responds, and the main post is to this day bandied around as establishing the point. Things don't work like that. If someone returns your serve, you're supposed to hit back, not walk off the court and claim the prize.

A knowledge of philosophy doesn't give you a basis of facts to build on,but it does load your brain with a network of argument and counterargument, and can prevent you wasting time by mounting elaborate defences of claims to which there are well known objections.