Mike,

I would say that that is somewhat true. About 8 years ago I was appearing before Congress with an NSAI delegation and with us was Micheal Laskow, the owner of Taxi. I asked him "What do I tell people when they ask if you are worth the money? I have my own pitch sources and have never used you guys."
He told me "Nashville is very cliquish and while we have some success there, we are based in LA so will have a better track record in film and television placements."
A month ago, I attended a TAXI meeting and the panel discussion was all about just that, where is Taxi's track record in Nashville at getting cuts. The panel discussion featured independent song pluggers like Sherril Blackman, some record company exectutives, hit writers and publishers. Essentially the entire conversation was about how inside the business has become for everyone, all running into the "Artists writing their own material" wall.
The truth of the matter is that where Nashville is now is where rock music was in 1964 when the Beatles shifted the parameters on the Writer/artist. They basically made it standard operating procedure of rock and pop music to be the artist was the writer, where as before there was a pretty clear line between the two. After that almost all rock or pop cuts were done by the band or the artist.
Country is simply there now. Artists are being signed as writers first and are "taught to co-write" before they release any product to the public. The 360 degree deal and the Internet have led to this nessasity. And for good or ill, that is the nature of the beast we are all dealing with.
So while it is not nessasary to live in a music center, it is pretty important to have a strong presence to break into the mainstream successes that actually make money.
I belive that outside writers are going to have to adapt to the fact that they will be having smaller independent cuts and overall things that make less money. To break in, you are really going to have to be writing with the artists. That is simply part of the shifting way music is done.
There will be more and more people participating in the journey, but it will also be spread out into more areas.The money issue alone has been greatly diffused.
So pluggers, publishers, TAXI, other sources, will still be a part of the equation. But the actual neighborhood will be a tighter circle.

Tis the way of things sometime.

MAB