Indeed, it is one of the three shvu’ot as Reb Eliezer pointed out. It is in Kesuvos 110b
It is the basis for the Satmar anti-zionist ideology. Also see the Tosfos there and the opinion of Rabeinu Chaim.
I find it odd that someone would denigrate living in Israel because of the “mitzva” , simply because they don’t raise sheep or donkeys. Besides, any person with some Talmudic knowledge should know that Petter Hamor or Reishit Hagez is a mitzvah kiyumit and there is no obligation to own a donkey or raise sheep. If yishuv EY is indeed one of the 613 mitzvot, it is an obligation, a hovat gavra.
Nonetheless, most everyone I know who moved to Israel did so because this is Home for the Jewish people. As I mentioned above, it should be obvious to all.