The Java 2 SDK organizes its vast collection of classes and interfaces into a tree-like hierarchy of packages within packages, which is equivalent to directories within directories.

If your packages are organized around tiers, this change will hit all over your system. In a word: A system organized around features, rather than technologies, have higher coherence.

for each method could have been placed in a stand-alone class).” Id. at 36. As a result, there “was nothing in the rules of the Java language that required that Google replicate the name groupings ...