It's not about who's pure. I can't control information once third parties have it. Pure today, evil tomorrow, who knows. I don't like sharing anything with Dropbox, Apple or Facebook either, and I try to avoid it.
It's just that I already use Google for searching the web, for maps, and for translation. And I use Youtube. I also store my contacts and keep a few bookmarks with Google because I use Android, but I'm close to stopping that practice.
Because of Google's search they collect too much information about me already, and I'm wary of them regardless of what they do or do not do. (Well, unless they encrypted everything client side with free software, utterly blinding themselves and their clients to everything I do)
I need to use Google a lot less, and I'm always on the lookout for ways to:
1) Use it less
2) Deny it access to information about me
3) Feed it false information about me
4) Encourage others to do all of the above