I think the issue is more that people who don't know better (probably the majority of people) will assume those ads at the top of the search results are just results, since they look very similar, just with a little yellow box that says "ad" under the main link. This box is easily overlooked by inattentional blindness if you're not looking to make sure you aren't looking at an ad.
It's all very well telling people to learn the difference, but most people won't, and that's not just their problem, it's everyone's problem if liars can pay google to effectively come top of relevant searches, since we have to live with people who will be potentially operating under dangerous false assumptions.
"And remember: Evil will always prevail, because Good is dumb." -- Spaceballs