According to Rodney Turner, there was a connection between the sin of pride in consequence of the Nephite's material wealth (see Jacob 1:15-16) and their "grosser crime" (see Jacob 2:22) of whoredoms. It was not just that some of the Nephites took pride in thinking that they could afford "many wives and concubines," it was that they apparently were using the scriptures (Jacob 2:23) to reason that their very wealthy status in society justified their actions. This despite more recent and specific commandments to Lehi (see Jacob 2:34). [Rodney Turner, "Morality and Marriage in the Book of Mormon," in The Book of Mormon: Jacob through Words of Mormon, To Learn with Joy, pp. 285]
Note* This situation of selectively following "old" revelations on polygamy, selectively interpreting scripture, and ignoring "new" revelations seems to be a problem even to the present. [Alan C. Miner, Personal Notes]