These other countries have no genuine love for palestinians, who they usually view as a pawn they can use to put pressure on Israel. They never take them in, their own borders are closed to them.
Jordan, Lebanon, and Egypt have had to deal with the
Arabs on the West Bank and in Gaza. They know how
corrosive their presence can be. These people have
tried to topple their governments.
Nobody, but nobody wants them in their nation or on their
border.