Well said.
I think a lot of these 'rules' are applicable to other areas, besides just performing. It also is more than just showing up on time.
For instance, our truck was going to be at one of the venues earlier than it should have been. Because we prepare for things to go wrong and to have time to act to remedy those situations, the part of the band that does the load in and setup was early. I had them wait down the road and show up about five minutes early.
Yeah, there were people already at the venue - but they've scheduled themselves and prepared for us to show up at a certain time. They might be, and probably are, busy with other jobs and don't want to disrupt their activities to come deal with our crew showing up early.
That might seem like a small thing, but the people in the venues are pretty busy and on tight schedules. Showing up too early just means they have to stop doing what they were doing, address us, and then take longer to get back to what they were doing.
And, as you said, this applies to more than just performances.
This doesn't just apply to being a professional musician, it's about being a decent person in life with all ones commitments.