Currently on a 40 man server, there will be 20 dedicated throwers, and another 10-15 melee toons who are throwing as well.
Exaggerating a bit are we?
As soon as your in range your being hit with 10 random throwing items and can do nothing but turtle.
If you expect to stand in the middle of the front line in the beginning of the battle without a shield then - yes, you'll die. That's the point. Throwing is a weapon like any other. While it does need a very slight damage reduction, most people die to throwing because they don't play properly.
I play without a shield right now and die to throwing no more often than to other weapons. I have no problem playing without a shield because I use tactics and don't charger like a madman. If throwing bothers you that much you should watch good 2H duelists and see how it is that they manage to have so many kills.
Most people who have problem with throwing have it because they think that just because they are good at dueling they should kill everyone, and non duel weapons are dishonorable. Well, we have bows, xbows and throwing. And cavalry backstabbing. And it's all part of the game.
Why the change? You have to think about that.
You're forgetting one were important thing: wpf change. Hybrids are now much better than they were. Many who before were not hybrids now are. This is a good thing and makes the game more fun for many, since they can play in various ways and not just always the same thing.
So now that hybrids are better, what do you think infantry will do?
a) Invest in another melee weapon? I've seen Urist promote this, but I still don't see much point in it right now.
b) Invest in xbow? Rarely a decent option, considering how even dedicated xbowmen are on average bad and can barely get any kills.
c) Invest in bow? You're not going to spam arrows if you're primarily infantry.
d) Throwing. Which can be done on the move, which can fill the remaining slots fully, be it 1 or 2 or three of free slots.
The fact is that throwing is natural addition of infantry arsenal. There's nothing wrong with infantrymen using throwing (as long as it's balanced of course).