The log is supposed to track multiple wagers, so that when their sum goes over 10k the ID is needed. The descriptions are very nebulous, so in reality without a name it is nearly impossible or useful to track cash transactions. It is their thinking that the general description will identify a player. In reality, you are right it does not help at all and is just more unnecessary paperwork (but I can't say that, can I?)
Would you expect anything less from the government when it comes to paperwork really?
I mean just look at your tax forms and you'll think Multiple Transaction Logs are entirely too efficient.