Does everyone here trust Google to ethically rank pages according to relivance regardless of participation in the AdWords program?

I have a website that was relatively no where in the regular search results (I was using Flash, and I hadn't yet implemented many of the known techniques for optimization). As a result I decided to begin paying per click to appear high in the "Sponsored Links".

Despite my recent efforts to optimize my PageRank remains at zero. Putting on my business cap, I began to wonder why a company like Google would ever give me to a higher PageRank when they can effectively keep me paying per click by keeping my site low in the regular search results.

Does anyone know of a reason to suspect Google is more ethical than the majority of profit focused corporations who are all about the dollars. Does anyone have any examples of sites moving up the regular results while still participating in AdWords?