The sole and only purpose for the bikini division is more $ for the promoters and NPC. You can go to a strip club or any popular beach on a summer day and find girls that could do the bikini division the next day. No dieting is required whatsoever. Most girls look the same year round. Now while I do understand the more $ part, it is a major pain in the ass that causes shows to run much longer than they used to.
In the San Diego BB championship, they had over 200 female competitors, most of them in the bikini division. The real insult is that they put them on first. While all the bodybuilders are sitting around most of them dehydrated from not being able to drink any water till after the pre-judging, they got to go on dead last while the bikini girls who I bet 80% didn't do a day of dieting much less be dehydrated go on first.