More languages just for the immersion part.
The idea is simple, to be able to translate from the language you are learning to your native one, even if it's not the language that you use to learn the new one.
For example, my native language is Spanish and i'm learning French from English, and when i use the Immersion section, i have to translate from French to English. Obviously i make mistakes at it and get down votes in consequence. I practicly don't use the immersion because of these two reasons, i get down votes and it's hard for me to make quality translations.