Agree. In my experience, the design team tends to work closely with the client and the dev team is either silent or left out. Silent, because offering opinions on how something affects the backend may be completely moot when the next iteration is developed; or left out, because the dev team can't communicate "you can't do that" to the client in a way that doesn't sound annoying.
The project manager's primary job is to keep the client happy, so they tend to overpromise. Which is weird, because (especially in Web design) they client was more or less happy with the limited set of functionality that Facebook gives them. They don't endlessly complain to Zuckerberg that their business's page is slathered in Facebook Blue, but if the Web site's buttons aren't the precise shade of mauve that matches their CMYK offset press business cards, they pitch an unholy fit.