"Terrible" is a subjective description, so I don't think there's any inherent contradiction between you calling Java "imperfect" and "flawed", and smanek calling it "terrible".

Generally speaking, it's very difficult to compare programming languages objectively. What one person might think is a flaw, another might consider a feature.

That said, I'm personally inclined to agree with smanek. There are a lot of design decisions in Java's syntax that are, to put it kindly, rather bizarre and perhaps not particularly well thought through. "Terrible" would be the word I'd pick as well, were I asked what I thought of Java's syntax.