I read their explanation, but if it came down to a court battle and you had granted someone the license to create derivative works you would lose a lot of ground. If someone has been given a license to create derivative works they own the license to that work, not you. They may not be able to use what you put there for commercial purposes, but once they have created a derivative work that could be used for commercial purposes. Or anything they want. "Derivative work" is a very broad term, and I wouldn't want the US court system to be involved in defining what that means when it comes to my Very Important Stuff. I understand what they're saying, and I don't think it's likely they'd pull something evil but since Drive is one of the few name-brand cloud storage options that has such ridiculous language, it's better for me just to stay away and not run the risk at all.
I am also not keen on a service deriving content information about my data, whatever it might be, in order to serve me ads. It's the same reason I stay off Facebook. I don't like corporate America using stuff I do online to paint a picture of me. I don't think it's fair and I don't think it's right so, again, I stay away and use services that don't engage in such behavior.
Edit: So, anyway, it sounds like no, they haven't changed their TOSs.