If the investment bank only facilitates the transaction, then the key incentive that could tilt the transaction toward having a sense of urgency, and as a result, indifference to the rating accuracy would be the personal gain of the individual/team attempting to process the transaction.
If that assumption holds, would tying in a performance based return to the banker who sells the security, balance it? That way they also have incentive to make sure the rating is as accurate as possible?
If so, then it seems that it would probably be resolved through legislation, because otherwise it appears to be an intractable coordination problem. Unless including a return for the seller based on the performance is something that occurs in the industry for other types of securities.
It's usually not proactive though. (PE firms get valuation checks before investment, but that's different than bonds.)
People just trust the agencies when they rate bonds highly, even if they shouldnt be
Rating agency who's customers pay a subscription price for receiving rating, should solve it?
Sellers need to convince buyers to buy their product. Sellers need to get their product rated in order to appeal to buyers. It's a one time cost to the seller to appeal to a large amount of buyers, and the higher the rating, the larger the pool of potential buyers.
Flip it around. How do you coordinate enough buyers together to pay for rating all the potential products out there to buy?
2008 provided strong empirical evidence that the market does not have the motive to solve its own problems. Markets are not obliged to conform to theories about how markets should work.
That's a real problem, and needs to be solved. It's not by itself a trigger for a financial crisis, though it's not hard to imagine it becoming one.