Well, no. If you're a developer or development manager working 70-90 hours a week developing and/or managing other developers, when do you have time to evaluate the market, keep track of every single competitor and potential competitor?<p>Do you run a spreadsheet loaded up with market data and demographics evaluating the potential revenue impact for all of the features you're thinking of including in the next release?<p>And so on and so forth. Product management is a full-time job on a substantial product. It may be that in small start-ups people wear many hats and you don't need it as a separate function. But if your team ever gets to the point that you can justify a full-time development manager, your team probably needs someone else with nearly full-time product management responsibility.<p>In addition to that, there are sometimes some benefits to separating product management from development management. Sometimes. Being a little divorced from the product's inner workings can provide a certain useful perspective. Hopefully, the product manager isn't wedded to the feature that a developer just spent three weeks building and can jettison it to ship on time :-)