Engineers think project managers and deadlines are a waste of time and a pain in the ass, while project managers think they are essential. Now that's what I call news! Whodathunkit!
This is business. Management wants to quantify everything to manage resources, manage spend, control cost, maximize profit, etc. It makes perfect sense at the same time that it doesn't really jive with how engineering works a lot of time. One thing for developers to keep in mind, though, is that *doing* something is never as important as *telling people* about how you did it. Metrics mean way more to the people who sign your paycheck than the code you write does and you should design your metrics accordingly.
The other component is PMs themselves. How many really good PMs have you worked with in your life? Grand total of 1 for me. Most PMs are people who don't really understand technology and have created a whole system of super-important metadata to "add value" to the process. When it's done properly a PM can help a lot, but mostly its just blustering and wasting everyone's time. These people want to protect their jobs, and their jobs are defined by timelines and metrics.