User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-4694695-20130828165613/@comment-16545476-20130828171244

Capcom made a reply that the old monsters which made a comeback in MH4 are only those with high popularity ratings. It's not that surprising since it's almost impossible to base the whole game entirely on new monsters, since there just won't be enough contents to go around. (They learned that lesson from Tri-.) Most of the monsters in MH4 came straight from MHP2G is due to the fact that in Japan this particular game is praised as the best game ever in the whole series. (Even though the best selling one is still P3rd.) The monsters within P2G gained quite a huge fanbase and thats why we end up with loads of 2nd generation monsters in MH4.

Zinogre made it in MH4 is just the same reason, it's popular.