In my opinion this is bang on. Millions of itty-bitty little classes that do so little themselves that they rely on eighteen other itty-bitty dependency-injecte

In my opinion this is bang on. Millions of itty-bitty little classes that do so little themselves that they rely on eighteen other itty-bitty dependency-injected "services" are the bane of our industry. They make it impossible to see how the code is really structured and works, hide state and data flow in the composition (which is where all the bugs then go to lurk), and make it harder to refactor anything without spending days changing all the tests. For some reason people who are fond of this style seldom use real implementations to test their code, even if those things do no actual I/O, preferring instead to have masses of brittle mock set-up, such that all the tests really prove is that your mental model of how the rest of your code actually works is broken, as you watch the system fail in production in ways that seem surprising to you. You'll then probably think you should do something about these failures and jump to the other extreme, writing brittle end-to-end tests that are very hard to actually diagnose failures in. Sigh.