I can't understand that either, but didn't want to argue the toss with them at the time. Tbh I was taken aback, it's not usual for an indie garage workshop to decline to do some work, usually the other way round
Update: this might explain why the garage declined: https://caradas.com/wheel-alignment-adas-best-practice/ but still, returning it back to factory settings should mean that ADAS works better, the implication is that hitting potholes etc and kncoking it out means your ADAS becomes unuseable / unsafe??