The majority of the people who interact with OSM will get a perception of it that's biased by the presentation. Even with the MapQuest Open style, Google Maps, to me, are far more pleasant to look at and easier to understand. The text seems to be rendered in a better, more readable way, and GMaps has a better handle on decreasing contrast for things that aren't that important, allowing more important features to stand out.
You can tell me that I shouldn't care, because you provide such awesome data, and I'm tempted to agree, but my reptilian brain will give me opposite feelings every time I try to look at your maps.