I'd guess performance / memory usage. In DD someone made a claim about how quickly gold could be made buying Rimmer's ale (through a dialogue option) and selling it, which sounded far fetched, so I ran a macro while I had lunch, or something, to fill my character's weight capacity to get the actual gold per hour value. I didn't bother reloading after that, and didn't notice until later that that caused a significant delay opening the conversation log (from virtually instant to something like 30 or 60 seconds).
You can
increase the limit.
