To decide that "no-knock" warrants are universally wrong because of this, though, is a lot akin to throwing the baby out with the bath water.
I've never said that and will never say that. I didn't see where anyone else did, either. There are hostage situations; barricade situations; known violent offender situations. Sure, there are reasons for No-Knocks...but just having a SWAT Team is not a reason; getting your SWAT raid numbers up for budget purposes is not a reason; serving a search warrant on John Q. Public because some uncorroborated slime-ball told you "he's dealing crack in there....now will you let me slide?" is not a reason.
When we take an eight man team and put them in the field for 5 hours to serve a simple warrant for arrest or search, we use up 40 man hours...and people get killed; families get terrorized. Does it not make more sense to put a two man team in the field for 8 hours and serve the subject on the sidewalk? Or maybe walk into their place of work? Catch them coming out of the house in the morning? Leaving work? Arriving home? Going to church?
How on earth did Law Enforcement get anything done prior to the No-Knock?