Rating agencies are not moot by any stretch, and for two reasons.
1. They have privileged information. They get to look at the books, the individual loans, whatever. I as an investor may be lazy and use them because I can't rate every deal myself (all laziness is relative), but even if I weren't and I went to look at all the public information... the rater has much more available to it to make a judgment. So they occupy a unique niche that one cannot duplicate.
2. Their current business model -- paid by the issuers -- everyone agrees is broken. However, we can fix every problem by making them paid by the purchasers. This will cause them to compete on quality, not quantity. Any time they stop working for you, you stop working for them; your incentive is to get properly rated deals not to get highest quality rating, and therefore that is their goal. As a corollary, they will pay for talent, because talent will produce better ratings.
Once you have a business model that requires competition on quality, not on quality, the brain drain has to stop. Why? Item #1 above: there is a demand that will not go away.
If the bailout has shown us anything, it's that if a business can survive on its own without government intervention, it really ought to; government involvement just means politicization. I'm open to arguments to the contrary, but the evidence is very strong in my opinion.