The importance is it usually is a good indicator of how you should view a Blocklandian. You should be scared as hell if they are a high BL_ID. Lower end IDs like less than 20k IDs are the ones who most likely know stuff about BL.
I see the majority of good players, those that act mature in game and that are also good at blockland activities, from 1.5k to around 12k, then 15k to about 23k, then 27k-28k. I feel like a majority of really low IDs are mature, but aren't very good at blockland, I assume because they used blockland a while ago, then quit, then came to try it again and find it has changed a lot and often they are unable to do what they used to. The ranges that I disclosed after this all seem immature, in admining and in BL_ID discrimination. The 20ks seem really bad about discrimination, mainly because their numbers are starting to get in the lower majority of blockland, and so they feel it allowable. A majority of the 30ks are just young and new, maturity and ability are limited.
Of course, there are always those exceptions, like a recent BLB (Blockland Buddy) is BL_ID 716 and he is a very mature, good builder. I have a recent BLB 37k that is really mature, and better than the average 20-late 18k builder. There are always exceptions.