I've been looking at it for the last 30 years and I'm not entirely sure I understand the answer to that. It's almost a rhetorical question. The rationale that I've heard about using it as a management tool is that it does limit the capacity and hence limits the pressure you would have on a resource.
The irony is that because of innovation, creativity, call it what you will, they've never done anything to limit the hold size. We now have a situation where we have 45-footers with excessively more carrying capacity than a 65-footer or even a 95-footer. It's a really bizarre situation that I've never been able to get my head around.