>>37455576It's the right size to me.
Decent amount of trainers, plenty of encounter zones, some of the best mons in the region, lots of hidden bases to scout, and there's a reward for checking out every corner of the area. To say nothing of Regirock and Mirage Tower in Emerald.
It's big enough to be immersed in, but not so big that you get lost--lot of desert areas fall into the pitfall of big, samey tilesets with no outstanding landmarks.
For what it offers and what it represents, it more than gets the job done.