Its not quite that simple. Well performed studies that are actually relevant to a particular project are _difficult_ to come by. By well performed, I mean free of biases and misattributions and relevant to your particular use case. For example, most of the links in the answers here (http://programmers.stackexchange.com/questions/10032/dynamic...), a question specifically requesting studies them don't have any significant empirical data. Further, if you dig deeper its also clear that studies often contradict each other. Further, lets say you try to do a cost-benefit analysis. How? Try to estimate how many hours a particular technique will save you and you run into the same problem people have been trying to deal with for years. Estimating the time it takes to do a project is _hard_. Add to that how rapidly things are changing in this space and how dependent the structure of code is on the application of that code, and its clear that we really don't have objective metrics for this kind of thing.
>Engineering tools affect both how you ship, what you can ship, and when you can ship it. The choice isn't arbitrary, and choosing involves careful reasoned thought, informed by real experience
This is far more revealing of how these decisions are actually made. Your experience and thought process may very well be arbitrary when contrasted with real data. It might as well be aesthetics and fuzzy feeling.