PSA: If you're not using a knee kicker on every single stair tread, you're leaving money on the floor.
I watched a crew in Denver last month try to hand-stretch a runner on a 15-step staircase and the inevitable call-back for re-stretching cost them half a day's profit.
Yeah, it's that same shortcut mindset everywhere... like people who don't measure twice before cutting, or skip priming before painting. It's a false economy that just burns more time later. @grant292's old boss had it right, it's about respect for the job itself. You see it in every trade, someone thinking they're the exception to the rule, and the client always ends up paying for that arrogance in the end.
That's just the cost of doing business right. Seen it happen too many times, guys trying to save ten minutes and then blowing a whole afternoon. A knee kicker isn't even that expensive compared to the labor you waste. It's like refusing to use a tape measure, just pride getting in the way of good work. They never learn until they eat that callback cost themselves.