Like every other group, there is some amount of groupthink happening with Wall Street analysts. They all came to similar incorrect conclusions because they are working with similar information using similar techniques towards similar goals. This creates a level of bias, even if banks didn't have incentives to write bullish projections.
Getting a diversity of opinions doesn't mean talking to 10 experts in the same field, but talking to experts in 10 related fields.
Getting a diversity of opinions doesn't mean talking to 10 experts in the same field, but talking to experts in 10 related fields.