Science is hard, especially if done properly. The least they could do is to spit teams in two groups, based on whether they use a technique or not (e.g. unit testing, using OOP) and see if it makes any difference. It's far from perfect, but better than nothing.

> That's because no one even knows how to start doing "science" in this direction.

I suspect the reason almost no one do SW science is that nobody really cares. Most people just repeat some dogmas they like, e.g. they say: "you broke liskov substitution principle, that's bad" without any proof.

I guess people just like flamewars (who doesn't :)