More lives are put at risk at times for Knocks, all depends on the situation. A packed NYC apartment complex and the guy has a illegal full auto? More danger to knock. A apartment like the one in the locke case? Not needed, but valid worry
Wait, you really think drug dealers have illegal full autos? That's a ludicrously unlikely scenario. The last time a criminal had an illegal auto I'm aware of was the 1997 North Hollywood shootout. The time before that was 1988 and it was a cop doing the shooting! A drug dealer with an illegal machine gun is basically a once-a-generation outlier, not something policy should be made about.
And while I'll agree there are times for no-knock and times that haste is critical, this clearly wasn't one. Dude was chilling on the couch. He wasn't doing anything that made an instant overwhelming response required like taking hostages, building a bomb, or downloading a torrent off pirate bay. Further, since they had a warrant at all, they
knew what it was for, that he was a drug dealer and not, say, a terrorist, so there was no reason to think he'd be cooking up explosives in his kitchen or that he'd kidnapped some peace-loving martial artist's girlfriend and had her tied up on the sofa. Why not just wait until he headed out to pick up a pizza and draw guns on him in a safer, more controlled position than a home where they didn't know who else was inside and there were innocent people in every cardinal direction to catch stray bullets?
To draw a comparison, most police departments today will not engage in high-speed chases. The risk of the suspect panicking and driving through a playground, or crashing a car full of innocents, is not worth letting the suspect potentially escape, and so they employ safer means like trying to track the car from the air via helicopter and if it escapes, well, better than the risk that he drove through a playground and maimed ten kids.
I'm of the opinion that no-knock warrants should be treated like high-speed chases. Hostage situation? Bomb threat? Active Shooter? Okay, those are time-critical enough to be worth it. But unless you can show that the suspect is actually a threat
this very second and people are potentially going to die if they're free even a minute more, it does not justify a warrant where innocent people are also going to potentially die from the cops kicking a door in and shooting everything that moves.
Drug dealing does not generally fit the bill. It's a crime but probably not one where an innocent person will die for each hour it takes for the cops to serve the warrant.