Whereas duckduckgo will return stuff that actually matches your search.
One upon a time Google was a really cool search engine. Entire books were written about how to use it wisely. E.g.
Google Hacks
100 Industrial-Strength Tips & Tools
Now, it's impossible to properly qualify searches. Quotes don't mean shit. Appending "&tbs=li:1" to get verbatim results doesn't mean shit.
Google just does whatever the hell it wants to. Which is probably great for the unwashed masses but really sucks for advanced users.