To be fair, Ruth married into the family. Twice. And to be entirely truthful, Jews have always looked down their noses at converts.
I was taken aside at my synagogue and told to tell no one that I was a convert. If someone asked if I was a convert, I was to turn my back on them and to ignore them.
It is considered rude to ask. Rude to discuss it. Converts are Jews. Period.
Yes, there is a bias, but most Jews don’t have the prejudice. Converts are protected from the ignorant few.
Ruth was considered a Jew before she married a Jew. (Or she would’ve not been allowed to marry a Jew in the first place.) Her children and grandchildren were considered full-Jews.
If they weren’t, we wouldn’t have had King David. He never have been allowed to become king if people considered his bloodline tainted.
“And to be entirely truthful, Jews have always looked down their noses at converts.”
Abraham and Sarah were converts, so no.
It is a specific mitzvah to accept and treat Jews-by-choice (real ones, with the mikvah and everything) the same as every born Jews.
A convert’s soul was present at Mt. Sinai and accepted the covenent, just like mine.