I find that the most productive Duolingo exercises for me are those in which I have to simply translate directly from my native language to the foreign language.
Those exercises accomplish much more than foreign-to-native translation, picking words from a collection, picking the word that describes an image, etc.
I would find it extremely helpful if Duolingo had a difficulty slider, or even a binary setting, that made it possible for me to do just direct native-to-foreign translations repeatedly.
It would be great if you could choose type's of exercises. The multiple choice and the word selections are really the easiest. They are OK when I do the lesson, but I'd prefer to turn them off for practice, leaving only translations and listening exercises.
I think you're underestimating how demotivated you can become. Doing a single repetitive exercise may become boring, reduce the chances of you learning effectively, and ultimately make duolingo worse. Most individuals here are not educators, so we(including myself) can't appreciate the need for various kinds of exercises.
I have no idea who downvoted you, but you have a solid point, and obviously the team agrees with you or they wouldn't have varied the excercises
The suggestion is not about not varying the exercises for everyone. It is proposed to make an option to choose only native-to-foreign translation tasks for practice if the user wants it that way.