Donkey,
God was not so much worried about the height of the Tower as he was concerned about it as an accomplishment done by humans without Him.
The all-powerful and all-knowing God (unless he purposely chooses to remain clueless, according to qua) was worried that the first coherent centralized administration might become so successful that it needed to be struck down because it might have achieved some great things.
Read about it in your own Bible at Gen 11:5-7,
"And Jehovah proceeded to go down to see the city and the tower that the sons on men had built.
After that Jehovah said: "Look! They are one people and there is one language for them all, and this is what they start to do. Why, now there is nothing that they may have in mind to do that will be unattainable to them.
Come now! Let us go down there and *obscenity deleted* it all up with a big stick!"
And with that order to His troops, Jehovah creates factions among the human race, with the stated intent of making sure that we will NOT be able to achieve all that once was attainable for us.
He obviously had his "all-knowing switch" set to off that day.
Eric