I have an opinion on this. I studied german for some months in Brazil and in Berlin and it's not a particularly difficult language. People find it hard because:

1. It's portrayed as hard, with hard sounds, and it's famous for being terrifying;
2. It's the only main western language that has declension. I actually understood what are these cases after I studied Czech, which had 7 cases for everything, while German have 4 only for articles. Depending on the teacher you had, it's very hard to understand what is the difference between the dative and accusEative cases; and
3. Germans are tough nitpickers. While, for most languages, natives don't speak correctly the formal grammar and are just happy that someone else is trying to learn their language and usually encourage them saying "wow, your <language> is perfect! I can't believe you are a foreigner", Germans seem to speak correctly with the formal rules and will try to correct every minor mistake you make even minor pronunciation differences. 

So although Czech is extremely more difficult than German, I found more difficult to study and practice German.