I agree, but it's ridiculous when there are 7 different "Andy's Coming" thread within the same hour. You don't even have to use the search feature for that.
I generally rely on the "live" feature...and just monitor that. Whatever comes up, comes up...whatever doesn't...I don't see.
I don't venture into "New Posts" unless I am truly bored, and I never use the main forum section screen unless I am posting a new thread and need to put it in the right category.
However, I get your point, and agree. One of the other forums I am a member of is notorious (at least from my observation) for merging threads even when the topics are merely similar, which helps (I think)...
I've seen threads merged here as well...though ops (mods...sorry, ops is an IRC term) here tend not to note that they did it...which leaves for a very confusing thread after the merge...not that it's hard to figure out what happened, but if you aren't paying attention, it can be confusing, I would imagine. Over there they do, which is nice, as at least you know what happened as a poster. (not a criticism of the mods here, btw, just an observation).
However, in a way, being overly obsessive with moderation and merging threads discourages posters, especially new or infrequent posters. And, active posters participating in the community is what keeps it thriving. I've seen IRC channels die, and forums die from overly aggressive moderation. It's a very fine line to walk. And I do not envy the mods here for the job they have.
On the IRC channels I Op (operate, not Original Poster, but moderate with @, which means operator in IRC, not @ as in Twitter or here...@ means something completely different there), on one of them we've had to let go of a lot of our more obsessive behaviors because...the channel was dying. It went from 700 active members to 200 in the past 4 years. It's disturbing, since the channel is 20 years old this year, one of the first, and traditionally one of the largest with active users, on the network. Though part of that is that IRC is a dying medium, part of it is also due to Op misbehavior (abuse of power, mostly...but it's a political IRC channel, so...neither here nor there, and not something to get too deep about)...as one of the oldest channels on that particular IRC network, it's sad to see it fade away.
Anyhow, my point is, Forum regulars who are checking the site every few hours (at worst) and every few minutes (at best, like me! <grin>) will follow along with most major thread topics, and know where to post.
Jane Doe from Hobokin who checks the forums a few times a week and just read something new on twitter she's excited about may not react the same way. Think how excited she is that she found out that if you yell "Andy's Coming!" the walkaround character might drop to the ground, and how cool that is.
Then, she comes back (a few days later) to find her precious thread is gone (been merged with another), or is filled with negative commentary (well...can't do anything about that, really)...
When she finds out about FP+, think she's gonna post again? Nope. She'll go to an even more unruly forum that starts with a "Dis", or just stick with facebook.
Anyhow, my opine. Just opine... <grin>