You've got 30 seconds you shot that, when the editor sits down to put it all together, definitely needs to be trimmed. But if you do that, it's 30 fewer seconds of "content". Your business measures output in terms of minutes of content, finished or watched. If you leave it in, the scene's worse, but how many viewers will stop watching because of it? Fewer than what it's worth to have that extra half-minute of "content". So it stays.
And operating this way, you can shoot 7 minutes of dialog that'd be trimmed to 4.5 minutes in a good edit (it's many individual shots, and most have at least a little on the beginning or end that need to go), instead trimming only what's absolutely necessary and get 5 or maybe 5.5 minutes out of it; do that over an entire 40 minute episode and you've saved yourself an entire longish scene that you'd have had to set up for otherwise, to fill the same time. Each set-up is expensive, so that's also saving you money despite being the same amount of "content".