What corroborating phone calls would you expect from an armed hostage-taking inside a private residence? Can you imagine the public backlash had this been legitimate, the police did nothing, and the hostages were injured or executed?
Equally we as a society need to be grown up and accept that sending a specialist armed team to respond to an event that has been shown to happen less often that people win the lottery is clearly unrealistic. Claims like this can be handled by regular policing forces who can call upon backup if necessary.
Are kansas city police regularly defusing hostage execution situations in private homes? Have they EVER done that?
Why are they optimizing for that situation? Arent prank phone calls the more frequent situation?
The whole point of taking hostages is to try and slow the cops down, and get yourself some leverage in negotiation. If the police are acting in a way that makes it seem like that's not going to work, then the hostage-taker will stop seeing those people as being useful as hostages, and start making decisions accordingly.