Complex sentence: Besides these problematic concerns, many have criticised applying the theory with too broad a sphere of validity--that the authors did not account for variables that reflect socioeconomic status such as class, religious indoctrination, and level of education.
Split into simpler sentences: Besides these problematic concerns, many have criticized applying the theory with too broad a sphere of validity. These critics contend that the authors did not account for variables that reflect socioeconomic status such as class, religious indoctrination, and level of education.