Bigger = Slower?

So here I am watching Tom Peters speak to a group of business people that are attending his presentation because they all desire to see their business grow. One problem according to Tom - that may not be the right thing to focus on and often big companies often equate to bad companies.
Think about yourself - maybe you have put on a few pounds, maybe you are a "little" out of shape and surely as you have grown older you have discovered more aches and pains? Your bigger - so to speak, but you are hardly faster or more energetic. Same proves true in business - with growth often a business finds themselves losing some of their nimble moves and stamina, not to mention flexibility.
So the point would seem to be - focus on the right things, the fundamentals and not the flashy things. In history all empires seem to have grown to a point where they suddenly cannot get out of their own way, they experience a social and financial collapse and then they implode - sounds a little scary doesn't it?