I think you're getting downvoted because you picked one of the hardest language pairs there is for machine translation. German grammar is really hard to parse, e.g. verbs being split with one part at the beginning and the other at the end of the sentence. Generally, figuring out which part of the sentence refers to which other part is quite hard.
Google Translate works a lot better with many other language pairs, so people might be downvoting because your opinion sounds exaggerated and doesn't line up with their own experience. It's also quite dismissive of the submission, which is never nice. The guidelines ask us to "avoid gratuitous negativity". I often find your comments to be quite negative, often unnecessarily so.
The French/English language pair was the problem machine translation research started with and has seen the most work. There are also greater similarities than most language pairs between those two due to the Norman conquest in 1066.
I accept your first point, but I disagree with your second - 1066 and all that notwithstanding, English is still very much a Germanic language, and grammatically very different from French.
You're right; I was arguing that French and English are more highly correlated than a pair of languages chosen uniformly at random and therefore easier for MT, but I could have made that more clear. I think the difference in accuracy between English <--> French and English <--> German does largely come down to historical academic preferences and data availability, as opposed to linguistic reasons. English <--> French vs. English <--> Mandarin (for example) is a different story.
Google Translate works a lot better with many other language pairs, so people might be downvoting because your opinion sounds exaggerated and doesn't line up with their own experience. It's also quite dismissive of the submission, which is never nice. The guidelines ask us to "avoid gratuitous negativity". I often find your comments to be quite negative, often unnecessarily so.