Frank Schnittger:

Nothing wrong with trying to reduce complex phenomena to more simply defined ones - or at least to try to explain complex phenomena with respect to a few variables and see how well those variables can explain observed data.  But you then have to understand that you are working with your model of reality, and not with reality itself.  And the model you use may well help to determine the results you achieve.  The observer (and his/her mindset/model) is part of the processes he observes.

There is no doubt that the "modernisation" model appeals to (even if it is not confined to) the "advanced" societal mindset which implicitly sees a progressive evolution from feudal/agricultural to urban/industrial and post industrial "advanced" "knowledge" based societies.

But the validity of factor analysis for "dimension reduction" is independent of the "modernisation" model or even the "modernisation agenda" you summarise as

It's about understanding (and helping) underdeveloped societies to develop and become more like us.

Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith