The purpose of the messy wiring on the right is to degrade service on the lines.
I kid... slightly. That's the result. The purpose is to save time. The excess ends (you can see a green wire pointing up from the metal bracket going nowhere) are sometimes called "pigtails." Some current can bounce back off of these and degrade service.
The proper thing to do is to trim the excess ends where you punched them down. The proper thing to do is to organize your wiring, and perform preventative maintenance including trimming the ends someone else failed to, organizing their wiring, tagging unidentified lines, etc... but these telco techs get ridden pretty damn hard in most places. Clients escalate everything, salesmen cut deals, bosses cut opex, and maintenance manning is considered a cost centre so while it may take 6 dudes to properly wire and maintain your area, you've got to do it with 3. You're going to leave pigtails, some wires won't get tagged, and the whole thing is going to be a mess.
... and I'm not one of these guys. I've just had to deal with the good and bad ones.