...the very essence of an enterprise (any enterprise) is that it is a bundle of labour and capital whose essential structure and identity is independent of and more persistent than the labour it employs. The identity behind its labour component is no more important than the identity of its capital component...
Mr. Patel was misquoted in the header, FTA he did not explicitly say "Turnover in Engineering No Problem", but let's assume he did say so in so many words. He is about 33% correct, all engineers are replaceable, and that is the main reason good engineers always document their work. But the question that is often ignored by business school 101-types is how much money and time does it take to replace a competent engineer? Can your enterprise afford the Project disruption and late time-to-market? Will your development still be relevant by the time it finally launches?
You argue that "capital" and "labor" are essentially equal to the identity of an enterprise. In a lot of enterprises that may be true, where either the labor is totally unskilled (light-bulb turners) and requires no training, or the labor is "certified and trained" and perform a set of narrowly-defined tasks, e.g. truck drivers, shipping, railroad engineers, airline pilots, etc. In product development, this ideal model breaks down. Engineering has no standardised training, and every situation or development situation is a unique learning experience, both for the enterprise and for the labor. That's why we have "project management" and development in the first place. History is full of examples of enterprises that made the mistake of treating their engineers as fungible, interchangeable assets. Products started coming out "a day late and a dollar short". Eventually they reorganised, split, made a splash with some big announcements and then disappeared.