Let's take an example. Let's say that there's a large Kemetic ritual that's about to take place and the public is allowed to join in- a random NeoPagan decides to attend, and walks in. Now there are several things which can happen from here.
Good Manners #1:
If NeoPagan has read any material about Kemetic ritual, she'll understand that the mechanics behind Kemetic ritual do not involve circles- she has decided to attend anyway, so she has clearly made peace with that. NeoPagan either attends the ritual, accepting this style of worship (politely asking questions about the ritual to the presiding priests or informed attendees after it's over), and hopefully has an enriching spiritual experience- or NeoPagan leaves quietly and goes back to doing the kind of ritual to which she is more accustomed.
Bad Manners #1:
NeoPagan is horrified that we're not casting a circle, and as the ritual gets underway she starts questioning the people around her, "Why aren't they casting a circle? OMG, we can't do this without a circle it's
dangerous!!!" NeoPagan becomes more and more disruptive to the ritual atmosphere, until she is asked to step outside the ritual area- or perhaps she storms out, making a dramatic exit.
Now again, from here there are more alternatives of what can happen- depending on how others react to our NeoPagan.
Once outside, our bewildered NeoPagan friend asks someone who is hanging around how these Kemetics could possibly do something such as holding ritual without a cast circle.
Good Manners #2:
Assuming that they know the answer, this person explains to the NeoPagan that not all systems of worship use circle casting, and encourages them to look into Kemetic ritual mechanics if they're interested in learning why this one does not.
If he has the time, the knowledge, and is willing, he may also go on to say that one of the purposes of circle casting in NeoPagan rituals such as Wicca, is to slip "Between the Worlds," to reach a point halfway between the spiritual and mundane worlds in which to meet the gods. However, in Kemetic theology our gods are here in
this world- manifesting quite clearly and comfortably in what many consider to be a "mundane" environment. There is no need to meet Them halfway, as They're already here. Furthermore, we use pre-ritual purifications to cleanse sacred space (remind the NeoPagan of the water and salt she was sprinkled with on entering the ritual space), and the power of our deities' presence naturally keeps undesirable entities at bay, so circles are not needed for protective measures except in very specific circumstances- which are generally unrelated to worship.
At this point the NeoPagan has the information she lacked before- she may ask a few more questions, or she may be entirely unconvinced. But at this point she knows what Kemetics do and why, and if she can not stomach involvement in a ritual without a circle then she will now avoid Kemetic rites, and she is now far more likely not to be a disturbance in future rituals.
If the person outside did not know the answer, then they might just say, "I don't know." Although it would be helpful to suggest to the NeoPagan that they ask some Kemetics.
Bad Manners #2
The person tells the NeoPagan that they're ignorant and/or stuck up, or is otherwise rude. The NeoPagan leaves the area without any answers, except that reconstructionists are snobs and Kemetics have no idea what they're doing. And though it's unfortunate, it's not entirely unexpected because this is exactly what has been demonstrated to her. This NeoPagan is likely to cause further disturbances within the Pagan community the next time she encounters a ritual which does not make use of a circle casting, and will spread the news on how badly she was treated to her acquaintances, who will likely also be resentful of the treatment and less likely to accept or explore the validity of non-circle casting ritual mechanics, and may also be disruptive in future rituals.
From this example, it can be clearly seen that the politeness of the first NeoPagan attending the event- the one who educated herself on Kemetic customs and did not create a scene- did more than simply protect the feelings of the priests who were holding ritual. It allowed a ritual to proceed more effectively, and everyone got more out of it. Likewise, the politeness of the person standing outside the ritual area did not simply protect the feelings of the NeoPagan who was scandalized by the Kemetics' lack of a circle- it produced a situation which was much more likely to yield a more educated person, who in turn was less likely to disrupt rituals throughout the Pagan community. In the case of the person who did not know or did not have the time to explain, but was still polite, he at least did not antagonize her, and make her more likely to be a future or further disturbance.