Paul Graham has posted his thoughts on what went wrong at Yahoo. As always, his thoughts are cogent and presented as a dense but accessible story. One of his statements, though, deserves some inspection:
At Yahoo, user-facing software was controlled by product managers and designers. The job of programmers was just to take the work of the product managers and designers the final step, by translating it into code.
One obvious result of this practice was that when Yahoo built things, they often weren't very good.
I expect Paul meant this as a condemnation of the waterfall, specify-and-build process, but it sounds like an attack on product managers and designers. Perhaps it is, as he thinks very highly of programmers and I wouldn't be surprised if the designers at Yahoo were… yahoos.