My objection isn't the indispensible part. I wholly believe that management, like politics, is a basic element of all human endeavors. And in fact, management is even more pervasive than politics: you can escape politics if you are a team of one, but you'll still have management needs. It's true that many projects don't have project managers, and still succeed, but that doesn't mean they didn't have management. If you are going to get groceries, you will (in America) go to your car, drive to the store, collect groceries, pay for the groceries, come home, and put the groceries away. If you do those tasks out of order, you will have problems. Even in the routine task of getting groceries, de facto project management is occurring.

My point is that project management already is indispensible. A tagline of "pointing out that project management is indispensible and that employing a qualified project manager is, in many circumstances, going to help you out a lot" would be (if only it fit on the maganize) a great tagline. But to state that we have to make our skills indispensible is awful for two reasons:

First, it suggests that project management is not already indispensible.

Second, and far worse, it says that Project Managers are people who, even though you don't need them right now, are damned well going to make you need them whether you like it or not. It's a marketing tagline in the worst way - it's about creating demand for our services, regardless of whether that demand is genuine or not. Yuck and double-yuck.