Why? There are SO MANY GHASTS. I have attached a screenshot. This has got to be a bug. The amount of Ghasts sounds is insane. It's like the Nether version of the buggy Lightening Storm when you travel very far. That is even HALF the Ghast out there.
It doesn't matter that there are this many when you bring the right gear. I went out with all prot IV armor, a looting III sword, a infinity bow and about 12 fire resist pots, lets just say I have about 40 ghast tears and over a stack of gunpowder.
Steps to surviving the ghast hordes: 1) Wear protection IV armor you take no fire damage 2) Run like a madman
there is already a prety long discussion about this issue in the News forums...Aikar is trying to tweak a setting for the mob spawning tweak they did. Hopefully this will be corrected soon as I know it makes the nether more than just challenging...kind of makes it annoying with all the wailing and fire balls and such...oh and of course the floor of fire that you end up with after these guys start to fire on ya...