The reason for using scientifically sound research methods is to try to
pinpoint cause and effect in the study. Although there may be anomalies
to theories like the ones you state, those examples help to show that
the underlying past theories do not hold true and either adjusmanets can
be made or the old theories can be discarded.
This is not, however, a good reason to discount the importance of well
designed research. This is especially true in the case of bees where
the variables are numerous.