Did the jewish people during the old testament time see being a gentile as an insult?
The Circumcision is a Token of the Covenant (which supersedes the written Torah), and the Covenant is what distinguishes a Saint from a Gentile, hence the Halo (to depict the children of Grace), and the Horns (to depict the children of Pride).
The terms were not meant to be an insult, though the Babes (being the immature beings that they are) used the term as a Derogatory, as if to say, not one of us, the misapplication is clearly spawned by Pride & Ignorance, which is ironic and oxymoronic in nature, like a pot calling the kettle black.
We experience the very same anomaly here in Hawaii, the term Haw’uleh (which is Hebrew & Hawaiian) lit., ‘Without Breath’ again to indicate one who is without the (anointing) Spirit, inferring one who is a Living Dead person, however the Babes use it to indicate ‘Not one of Us’, they simply do not understand that when they assume a Prideful stance that they themselves are acting Haw’uleh.
Another word used Derogatorily is עול which translates Babe and or Evil (depending on the context), the term identifies someone who is both precious and אפל immature, whereas the term רשע (ra’shah) denotes inappropriate, incompetence, and unjust.
At either rate when a עול and רשעים turn from their Ways, they are no longer to be referred to as Evil and Wicked, likewise those who forsake the ways of the Gentiles and are grafted into the Vine, they are to no longer be referred to as Gentiles, to do so is to wrought Confusion.