There are many things that are legal but still damaging or wrong. In many cases (including this one, IMO) we as a society should be able to know more about the behavior so that we can deal with it if it’s problematic.
I own that house and I don't want you to know who I am - and this is part of my hard-earned assets protection strategy.
Why your casual curiousity to know is more important than my desire to legally own the property without disclosing information about me to everyone and their cat?
If they want to complain - they can do so to local authorities or local regulators.
Complaining to your asshole neighbor even knowing who he is doesn't help to resolve your issues any better.
Anonymity essentially takes all of that and ejects it. Without a new legal framework to replace it (that you almost certainly will like less because it will both cost more, and demand more access to you by the state), demanding that formal legal means be used in all contacts with you is demanding that your neighbours pay significantly more to achieve mutual ends. All while giving the rest of civil society the brush off: "I've got mine, you can kindly go have a nice day."