I think part of this was good ole Calvinist predestination... God has been laying out a drama on the face of this earth. He arranged for certain Jews and certain Gentiles to populate the earth at certain times so that it would come out this way, without violating their free wills... a gold rush of Gentiles and a trickle down to near nothing of Jews (except those who adopted a Gentile style Christianity).
The complexion of the picture will change in the future if common takes on the book of Revelation (and other prophetic books) are correct. Once more Jews will come to the fore and Christianity will regain an explicit Jewish character.
In the meantime, certainly the Jewish Paul says for the Gentile Christians of the churches he wrote to, not to sweat it! Remain in whatever state you were in (circumcised, not) when you came to the Lord. Deal with the issues on a case by case basis.
As I said earlier, I see a time coming when Gentiles will want to be Jewish... but this will be Christian Jewish. I could see, for example, Muslims getting won over this way, something we’d scoff at today.
It's hard enough to be a Gentile Christian anyway.