In my experience, being on time isn't viewed as rude, but it is viewed as a nuisance, reflecting poorly on other people.
I had a Chinese tutor who got pretty upset that I would show up to lessons before she got there. Her first approach was to assure me that it was ok if I showed up later. Eventually she responded by showing up very, very early.
In a different case, I had an appointment to meet a friend, and she texted me beforehand to ask whether I'd left home yet. Since the appointment was quite some distance from my home, and I couldn't predict the travel time, I had already arrived, but upon learning that my friend dropped everything to show up early... and asked me why I was so early. I don't see a problem with waiting for a scheduled appointment if I show up early! But apparently other people do?
Presumably the tutor was being paid. If you arrive late, you are cheating yourself of your full time slot. Unless the tutor operated on a model of, “45 minutes starting whenever we are both here”.
> Unless the tutor operated on a model of, “45 minutes starting whenever we are both here”.
I would be unsurprised if that's how she thought about it, but it didn't really come up.
My sense was that, since she was the service provider and I was the customer, she felt that it was inappropriate for me to be waiting for her.