I like the current arrangement -- in fact, I would like it even better if it included everyone who has a particular name as "Other Last Name."
The fact that genealogy has conventionally indexed people only by their original last names likely has something to do with the fact that traditional genealogy was heavily focused on male lineage and the associated paternal surnames, and pretty much ignored women (with the exception of aristocrats). With growing interest in documenting all of our ancestors, there's a growing need for tools that help us locate and keep track of the women, in addition to the men. The inclusion of current last names on the surname list is one such tool.
I frequently use the surnames lists to locate an existing profile and find duplicates, primarily for people born in the 1600s and 1700s. For example, on a number of occasions, I've been able to identify and link previously unlinked profiles for offspring, siblings, and spouses after I sorted a surname list by birthdate and noted people in the same time period and place as the person whose profile I started off with. The fact that these lists include women who had a particular name as their current/final last name often helps with this sort of search, and others. (And because the LNAB is included in parentheses, there's no risk of confusing women who acquired a name by marriage with women who received that name at birth.)