This is always true. By that logic, we should SWAT every warrant, every traffic stop, every parade. There should always be a threat assessment.
This would imply it's all #2 ("publicity"). Which means police forces and public defenders are using the threat of extreme violence as... a PR move? Against American citizens who are innocent until proven guilty in a court of law?
The irony is cops do this to protect themselves, and statistically speaking it has the exact opposite effect.
(1) The law enforcement decision makers are unaware of the research (which is unlikely), or
(2) The stated motivation is not the actual motivation.
... which turns out to be the same calculation they used all along.
Knock.
Depending on the response from the inhabitant, either take them into custody or call for backup.
Well, you could do some basic investigation before an arrest, which would both give you in most cases a good idea of the threat profile and often give you a better idea if the information you've been fed actually accurately represents the facts.
Its not "investigation" is, you know, right there in the name of the agency, or anything.