Actually hes right. I also have 152 mounts, with only 1 Blizz store mount and none of the 1% raid drops that were 100% before.
I can easily get more with halaa mount and vial of the sands and tournament mount, so please, accept it.
Azure Drake (RNG)
Blue Proto Drake (RNG)
Crimson Deathcharger (massive gold/setting up heroic raids)
Dark Riding Talbuk (Find people ACTUALLY available in Halaa)
Fiery Warhorse (RNG)
Grand Black War Mammoth (RNG)
Raven Lord (RNG)
Rivendare's Deathcharger (RNG)
Subdued Seahorse (Camptime / massive gold)
Swift Razzashi Raptor (RNG / unobtainable atm)
Swift White Hawkstrider (RNG)
Vicious War Steed (Getting a semi-decent RBG group going)
Tyrael's Charger (IRL money)
Vitreous Stone Drake (RNG)
Winged Guardian (IRL money)
X-53 Touring Rocket (Recruit a friend)
Sea Turtle (RNG)
It isn't easy, the fact that you were lucky enough and had the gold/real money to get this many mounts doesn't make it easy it just makes a person persistent in gathering mounts, some of these mounts I have been farming for quite a while, years even in the case of the fiery warhorse. It WILL take a new player ages to get to 150 mounts and that's what Blizzard will look at, not at "oh well this person has 200 mounts+ we must make an achievement!
Yes I agree there should be a next tier achievement but no, it isn't easy to get there.