Problem is what they think is ass covering is doing nothing. As it could be reasonably argued in court that the notice is 'white noise' that a pilot can't reasonably sift through and compensate for, and that it is the aerodrome operators responsibility to ensure any infringements of published data are adjusted in the tabulature, not just raw data supplied. If you were to collect one such tree or fence that is.
A bit like the rules governing lengthy contracts for general goods, once the wording gets too extensive it's considered unlikely anyone would read it and is therefore voided.