Sure. Some of the more sophomoric and/ or navel-gazing and/or pretentious stuff annoys me. But I don't think that translates to "just don't bother," at all!
Two main reasons:
1.) I think that thinking critically, itself, is a valuable skill. Not just accepting whatever is "conventional wisdom" and not just saying "yeah whatever." So if critical thinking is honed by engaging in these kinds of discussions, cool.
2.) While I don't necessarily think us message board people will come up with anything big, I think that these questions are important to ponder just in general (some more than others, for example I think questions of governance are more important than questions about the meaning of existence). Sometimes there are big advances, sometimes just a lot of little incremental ones, but I don't think society is well-served if anything abstract is sidelined.
Plus, I know you're talking about philosophy, but "Do we benefit as human beings by continuing to discuss questions that have no guarantee of a definitive answer?" applies to a lot of other things that I think are very worthwhile too, especially when it comes to science. We'll never find out if we just give up because we don't have a guarantee that we will
find anything out.