Cute idea, Reddit Inc., but ultimately flawed. You're simply showing that you don't understand your own users and how they use your platform.
Comments and text posts do play a huge role in Reddit, and those will probably get translated. However the topic is more often than not introduced by an image or a link. Text in the images will not get translated, and for the link you'd need to rely on a second machine translator.
Furthermore a lot of the comments require further context, that won't become "magically" available just because you translated it. I'll give you guys some examples:
- "Is it him or is it not? Of course it's him! The showgirls!"
- "I'll give you an gold award that is worth more than money! A-hai, hi-hi!"
If you read those and thought "what the fuck? I don't... I don't even..." - exactly. You might get them if you speak Italian (first one) or Portuguese (second one), but then you don't need the translation at all.
And you'll likely not need the translations from English to another language, given that ~half of the Reddit userbase are native English speakers, and the other half is heavily biased towards people who know English as L2+.