I've noticed this, too, and I've been thinking about it a little.  I've read threads where I see some good posts and have found myself out of sMerits that I would have liked to have given out, posts that hadn't yet been merited.  If you asked me point blank to tell me exactly what those posts were, I would not be able to tell you.  I just see them and move on if I don't have the sMerits to give out--so my point is that when people complain that they see really good posts that are going unmerited, they might not be lying.  They're just not keeping track of them.

Sometimes when I see a post or a user who should be getting merit but isn't, I'll bookmark the post or the member's profile for when I have sMerits to distribute (shouldn't be a problem now that Theymos upped my allotment), but I'm pretty sure most of the lower-ranked members who are complaining about this stuff aren't doing that.

And yeah, this thread so far is a disappointment.  Maybe Jr. Members are now starting to accept that they might not ever make it past that rank, that merits are very hard to earn if you can't write English very well in the main section, and they've given up hope.  I don't know the reason, but I would still very much support a "report post to merit source" button if there were some restrictions put in place to reduce the amount of spam that would inevitably get reported.  This is one of those things I'm hoping Theymos might consider.