I agree with you, but Anki is a generalized flashcard SRS memorization tool, not specifically made for learning Japanese, so it's not within my area of critique; I'm thinking of apps similar to Duolingo. It works extremely well because it helps you memorize very efficiently. One of the few applications that will indeed boost your learning by a lot. Anything requiring manual input rather than a simple Again or Good button choice tends to be worse. Any Anki deck requiring manual input as an answer should not be used.

I assume you're thinking about translation flashcards when you say that manual input should not be used, but I get a lot of value out of dictation flashcards in Anki: the front plays a recording of a sentence, I type in what I heard, and I mark myself correct if I wrote the right sentence and understood its meaning.

With translation, the problem is that there's often many correct answers, which makes it difficult to distinguish wrong answers from unexpected correct answers. But sentence dictation usually doesn't have this problem (barring puns with homophones.)