I don't think it's fair to chastise Eugene's family for wanting their son to marry a Jew and being upset that he isn't. I think it's totally twisted around to say they left Russia because they were persecuted for their religion, so they should be open and accepting to their children marrying people of other religions. I see it the other way around- they moved from Russia so that they could be Jewish without persecution. I'm pretty sure that their burning desire of wanting their children to have the freedom to live openly as Jews did not include their children marrying "out" and in their minds, having their Jewish lineage dying off in the very next generation. From what I understand, a child is Jewish if their mother is Jewish, so it is probably killing them that their grandchild is not Jewish, especially when their Jewish identity is so defining for them and is the main reason they immigrated. I also don't think it's fair to make an assumption that Eugene's parents aren't acknowledging their grandchild. We don't know that they've done that. Even if it breaks their hearts that he isn't Jewish, for all we know they are loving grandparents. Just remember that this is a reality TV show, so this are edited for maximum dramatic effect.
I don't think it's right for Eugene to ask Samantha to convert because that is something she needs to want for herself for it to work, but I understand why he did. It really seems like out of all the couple on this show, these two did the least in making a conscious decision to be paired with one another for the long run. These big issues are the kinds of things a couple works out or breaks up over as their relationship grows, but with Eugene and Samantha getting pregnant after dating for just a month, they didn't go through that process.