Why do the children and grandchildren of Palestinian refugees hold refugee status while no other children of refugees get the same status ?

One of the most prolific hasbara myths is that Palestinian refugee numbers are falsely inflated because they include the generations born in exile, who critics allege are not “real” refugees . In fact, derivative refugee status is standard policy across the UN refugee regime.
The UN High Commissioner for Refugees states that:

“if the head of a family meets the [refugee] criteria … his dependants are normally granted refugee status according to the principle of family unity… the principle of family unity operates in favour of dependants and not against them … [and] does not only operate where all family members become refugees at the same time.”

In other words, as long as a group’s displacement remains unresolved, refugee status extends to all those experiencing it, regardless of when and where they were born. The alternative would mean that a Syrian baby born in a camp in Jordan, for example, would be ineligible for essential relief services from the UN refugee agency.
What’s more, protracted refugee crises are the norm rather than the exception. The UN currently estimates that 78 percent of all refugees worldwide are living in a protracted displacement situation.
A view of Jenin refugee camp, West Bank, March 8, 2015. (Ahmad Al-Bazz/Activestills)
It is true that the Palestinians are experiencing the longest-running refugee crisis, having lived in exile for 75 years, but many other cases of displacement have also lasted decades. For example, there has been a sizable Burundian refugee population in Tanzania for 50 years, while elsewhere populations of Vietnamese, Afghan, Somali, and Iraqi refugees have all lived in continuous exile for more than 40 years. The reality, then, is that the Palestinian refugee case is unusual without being exceptional.