A policy that police do so when it is reasonably foreseeable that they could be reasonably mistaken for violent trespassers would have very limited opportunity for deliberate exploitation by criminals, and would also provide a strong incentive for even bad police to avoid the occurrence of such situations on the first place, whereas the status quo encourages violence-minded cops to engineer such situations when they can also engineer a lopsided force advantage over anyone likely to be present.
>>dragon+(OP)
I think its much simpler to just eliminate the situations where the police could be reasonably mistaken for violent trespassers, i.e. no knock warrants, instead of having a seperate set of rules of engagement for no knock warrants.