I'm reminded of the Phillips curve which relates inflation and unemployment. If you graph these data points for the 1950s and the 1960s, you do get a great correlation. But extend the graph to the 1970s and the 1980s and the data instead looks a lot more like a random scatterplot. Yet the concept is important enough to be covered in Economics 101 textbooks. To me, it seems a case of economists clinging to models that predict the opposite of reality, and it contributes to my general impression that economists prefer mathematical models even if their correlation to reality is poor.
As for interpreting trends unwisely, isn't that what you're doing by noting a lack of inflation and arguing therefore that fundamentals don't matter. Common sense says if you give out more cash, people can bid up prices higher. There are undoubtedly variables not accounted for in all economic models. As the statisticians say, "all models are wrong". But those unknown variables can turn on you too. Every bubble consists of people ignoring fundamentals because they don't fit the recent curve, then getting burned when it crashes.