Dwight in a recent comment has raised a good point. Upholding baptism as the entrance rite of the church does not appear, at first glance, to be welcoming. And this because the concept of a welcoming church has changed over the years. I can't say I have loads of anthropological insights to back this up, but it seems the Christian understanding of welcoming included the transition from one community to another. This being the case, the baptismal rite as the entrance rite and transition from one community to another constituted a rather lengthy process of initiation culminating in full entrance into the church, communion, etc.
A crass analogy: When you went into Mr. Roger's house with him on his show, you weren't just there. You first had to take off your shoes, change your sweater, sing a song, and only then were you finally there. What is more, to enter into the little imaginary world where the train went, you had to first do all this and then imagine your way in along with Mr. Rogers.
Today, we track all our dirt on our shoes inside the house, leave our coats on while we're in, never imagine anything of much together, leave without a trace, and fail to offer a glass of water to the visitor while they're there.
So we've got issues of hospitality abounding in this discussion, but like false understandings of hospitality. Not hospitality as peace tolerant co-habitation, but in the view of the church, hospitality as that radical gospel act that changes both the host and the guest.
This is why, among other things, to maintain the unique hospitality practice of the Christian community, the Eucharist cannot be a meal for just anyone. We have plenty of meals that can be like that. Every time I eat at Culver's I have a meal like that, or invite my neighbors over for coffee. The Eucharist is a special meal of mutual recognition where those who are already baptized, who have the shoes and the new sweater and even a new mind, sit down at the meal of their Lord, who says, come, all is ready.