Attorneys will often include provisions in partnership agreements, LLC Operating Agreements, shareholder buy/sell agreements, etc that they have in a "model" or form version of the agreement. The language moves from agreement to agreement because it is what they have always used, even though they don't necessarily understand the nuances of the text. Often, these documents go into a file drawer with no further thought until things start to fall apart.
It's only then, when trying to enforce the agreement, that anybody discovers that the document (a) doesn't reflect how the parties were actually managing their business, (b) misuses terms of art in the accounting and finance worlds or (c) omits critical language necessary to actually implement the provision.