Hi Steven, et al,
When I did my course (diploma in media studies) we had several classes where publisher's representatives visited to talk. Many manuscripts submitted in Australia they said, don't get read, unless an agent is pushing the author's barrow for them. Even then, it is hard. The reps used the term "hundreds", and seemed to be referring to at least one per day. The occasional one gets noticed.
However, I have had the misfortune to start many books - some by very popular authors and from well-known publishing houses - that are barely at the first draft stage. Some I force my way through, others I give up in disgust and return them to the library.
The wordprocessor is a great tool and a curse - it gives ready access to the means to "complete" a manuscript, and I tend to feel that self-publishing and the proliferation of sites where a book can be put out to the public are in the same boat.
I think the comment about market suitability is quite relevant - if I published non-genre ("mainstream" in Oz, or literary) novels and received a manuscript for a genre novel, I would not view it favorably, if at all.
MSs that can essentially go straight to print? I think very few, unless the author has been previously published. Too many writers - amateurs and professional alike - are insufficiently critical of their work, and in many cases lack the skills to present a polished piece.
It used to cost a lot to publish a piece - editors, cover artwork, printing, and so forth - and this encouraged conservatism.
We had a writer in Oz a few years back, who was seen as being very marketable, and her work received some critical support. Her book hit the shelves and she was hailed until a very well-known writer pointed out the strong similarity between passages in her book and something he had written years earlier. The term "plagiarism" came up before the books were pulled from the shelves.
The publisher lost a packet on that one. They thought they did everything right, but still got stung. Conservatism is not a uniformly bad policy.
Cheers,