It's because the balance shaft bearings are prone to seizing, which causes the drive sprocket to sheer off with potentially disastrous results!
This comes up a lot on the TFSI group on fecesbook and is made out to be a super common problem (it isn't), but the one thing no one seems to answer is: "Does deleting the balancer assembly noticably increase NVH?". Silence. So I'll take that as a, "yes it does". In which case a delete is not for me personally!
The full delete involves removing the entire thing and retrofitting the older 1.8T oil pump, which necessitates mods (of the drilling kind). 1.8T pumps used to have chain snapping issues back in the day, so it's kind of like jumping out of the pan and into the fire.
A semi-delete involves just disconnecting the balancer shafts and 'freewheeling' the drive sprocket.
I'd be interested to compare the part number of an early AXX pump assembly to a later one from say, a BYD or CDL to see if VW have updated it, but at ~£1500ish (last I heard), it's not a cheap thing to replace.