If we want to post on other tribes , we do not have to use the POB hashtag. POB is for POB.

No, this is wrong

We do not discriminate in this community

POB is for everyone. There are contents that may really need to be posted on other communities, but that doesn't mean the POB tag cannot be used. It can.

We are built on HIVe like every other community, and even though we are growing rapidly, it doesn't mean we should neglect other communities, and try to stand alone

No, if we want to be on our own, we will have to leave HIVe completely.

But we do not want to bite the hands that fed us, so we support other communities as they support us

The only thing you would have said would have been to encourage more users to use our frontend regardless of the content of their posts

It will bring us credit in terms of traffic and search results.

You shouldn't ask them to stay away, no, draw them close. Let them see the benefits of posting from the POB frontend.