Why is ecological validity not prioritized in studies conducted in theory-testing mode?

The purpose of theory-testing mode is to find evidence in order to disprove, refine, or support a theory. As such, generalizability is not the aim of theory-testing mode.

Due to this, the priority of researchers in theory-testing mode is to eliminate alternative causes for relationships between variables. In other words, they prioritize internal validity over external validity, including ecological validity.