I disagree. This is simply better ant style, and the technique is a specific example on the ant import task documentation:
Part of the ASF principles and the choice of the Apache license is to encourage outside contributions. While this has no positive (or negative) effect on the project build itself, it makes it easier to develop code that will later be contributed, and encourages that development to be tightly coupled to the existing build process. This means there will be less work later to add it as a contrib/ project, which is good for everyone involved.
Do you have any specific complaints about the patch? If it is zero-sum for the existing codebase but positive for future contributions, it seems to me like it's a net win.