> My belief is that it all stems from the fact that Java doesn't have a REPL, so programmers use "test-driven development" to get the same level of interactivit

> My belief is that it all stems from the fact that Java doesn't have a REPL, so programmers use "test-driven development" to get the same level of interactivity from their code. It's not the same thing though. REPL gives you fast feedback once. Unit tests you build by following TDD are there to stay.