I didn't think that was a good idea as it means thieves can practice on the lock. Commute is not a problem as the bike will remain in my sight at all times behind a locked door. The problerm is when it gets left elsewhere
What you say makes sense, but a couple of observations;
I wouldn't leave a lock attached to a public stand, because some see that as anti social and the council have been known to remove them without warning. I leave mine at the stand at work where the cyclists know each other, but there is no presumption that a lock means a stand is "reserved"
As far as I know, Thieves removes locks by brute force, not picking or anything as subtle as that. So they can't practice. A concern might be pre-tampering, like weakening the lock or chain in a non- obvious clever way. On balance, I accept that risk where I park my bike at work, because it is a relatively safe area.