Why are so many culling their follow counts?

I thought it time to trim out the deadwood among those I follow on twitter today:: Those who have stopped tweeting, or who have shifted channel, or turned out not to be the interesting folk I thought they may be initially, etc.

image via http://www.charlesstone.com

In the process I spotted a disturbing trend. Using one of the many twitter management tools I found several people who I follow and quite regularly engage with, who don't follow me.
I'm not talking about the 'too much attention to cope with' folk, the @stephenfrys  or @bbcbreakingnews of this world (for example), I'm talking more the moderately interesting or those who may have done a lot of conference speaking, or (heaven forfend, and trust me, I'm aware of the risk in every word of this, those who have puiblished a book). It's not that they aren't simply following me back (quelle domage), it's that they appear to be following almost nobody.
I mean if you are following sub 500 and your follower level is closer to 50,000, well something seems to have gone wrong there.
For a start, that doesn't happen organically. You take the decision to cull.
Some may do it for ego and aesthetic reasons - look at the ratio on that!
Most would wrap this in the reason of 'signal versus noise'.
Which is just so much bs unless you happen to be using twitter 24/7 and have text alerts pinging on your phone each time you get an @message. I need back up in case I miss the thing that's important to me being tweeted or retweeted. 3000 folk gives me that cover. Always has so far.
It also gives me diversity. If I don't open up to outliers, how will I see the extreme moments that often have the most impact on our world (the Black Swans for those of an Anti-fragile bent).
I've always tried to follow back pretty much everyone who follows me. But even  in this I have started to hit a limit. Mine is around 3000. If I start following more than that I go seeking to clear out some deadwood - the folk who are not, or hardly ever, contributing to my time line.
And this is where I find it odd that folk with big follower numbers to feed (for surely their's is a broadcaster-audience relationship) feel that they can learn enough about their world from following less than 500 folk to provide a credible curation.
I salute their ability to select. I salute their trust in those they choose. I salute the trust their audiences confer on them.
But I can't help thinking they are helping to accelerate Twitter towards being the place where broadcast and self-promotion dominates rather than a place where adhoc communities of purpose form to get things done (which remains its promise).
Culling those you follow is - in extremis - like limiting your view to that from a prison cell. Why volunteer for that?
I would be delighted to hear from people who have taken this radical approach (culling those they follow) to reduce their exposure to noise or for whatever reason they have, and how it'
s working for them.
But until I hear a very good case I'm going to stick with the theory that one extra node on your network doubles its value: and that this 2n proposition can only happen if the connection between nodes is two-way.

OMFG! Even when we're looking (hard), we can't see

I was lucky enough to be in New York's Times Square on Sunday. It is the most message-intense place I know in the physical world.
I was there to vist ToysRus for some daddy's-away-on-business guilt shopping.
I've been to the ToysRus on Times Square before - last year when I visited with my wife.
I'm sure I remembered exactly where it was. But I couldn't find it.
I just couldn't tune out enough of the visual noise of Times Square to find what I was looking (hard) for.
Turned out I was stood right slap bang outside it. (About where that A-board is in the picture below).
The wood is so, so, so hidden in the trees.

Which is why I like the picture of the OMFG billboard (left) I took. Dunno what it means in the US but it's pretty explicit in the UK.
A very loud signal, you might expect? Yet no one, no one! was looking.

Times Square is quiet compared to the totality of messages we have thrown at us daily. That's why we no longer see them. But, just like those pedestrians walking by, we are looking where we are going.

Which is where I'm headed with some widget strategy work I've been doing: The user is the destination now.

A rare handful of things are so important to us that we are prepared to look really, really hard for them - like ToysRUs in Times Square. What has made them important is an awesome experience. Think how awesome the Times Square ToysRUs has had to be to achieve this. This is a toy shop. A toy shop with a ferris wheel, giant Barbie House and animatronics dinosaurs throughout. Oh, and a brand...

If you can't match that we won't come looking. Because looking is becoming increasingly Times Square-hard. And if you make us look too hard, we'll give up and go elsewhere. Or ask a friend.

For the rest, if you want your message to be part of our walk through the Times Square of life, you are going to have to be something so useful to us that we're prepared to take it with us and place it where we always head back to, or somewhere our friends will take us by the hand and guide us to.