Every unit has its purpose. Infantry blocks are not meant to route the enemy and win the day. That wasn't the purpose historically, and it isnt in a game of Warhammer. Look at it this way. Could a unit of Knights take a charge from an infantry block or another hard hitting unit? No, it isn't the purpose. Trying to make basic low-point infantry both an anvil and a hammer is changing a fundamental aspect of the game. They take the charge, and they do it better than any other unit in the game.
Now take a look at Elite infantry. In some respects, they are meant for this dual purpose, as they are usually quite hitty. However, when you're paying 12-16 points for a model where only the front rank actually gets the bonuses of being elite infantry, you are at a clear disadvantage. Lets say you have a block of 20 Chaos Warriors. The front 5 are in fact elite infantry and can dish out some damage, while the other 15 only provide you with +3 CR. That's a huge point sink for a minimally more combat oriented combat unit as compared to a cheap unit such as Clan Rats.
Now the problem that the HE have, is that they have these really high point infantry units that are even less effective than Chaos Warriors or Dwarfs. They die just as easy as a 3 point Night Goblin with HW+S. You just can't make that work unless you make them more protected (higher T, AS, or WS which is really out of the question), or give them the ability to avoid massive casualities a la strike in initiative order. This helps put them on the same level of effectiveness, or maybe slightly higher, of other elite infantry such as Chaos Warriors or Saurus Warriors. Think of it this way. Are you more scared of charging into a unit of Saurus Warriors with spears or a unit of Spearelves with strike in initiative order? I don't know about you, but I'd feel much more comfortable with S3 T3 elves than S4 T4 Saurus.
