Tournaments - sometimes not losing, is more valuable then winning chips - I think this is what he is saying.
One of the unique and interesting concepts of tournament play is the theory of "stack size leverage" situations crop up that are very good purely because of the size of the stacks, here's a gd example...
8 handed NLHE tournament, the blinds are 500/1k and the ante is 300. The player in middle position wakes up with

and he has 38,500 - he has a decent stack and a very strong starting hand, he raises to 2,500, which is a perfectly fine play.
You are next to act and you have

and you have 46,000, you make it 6,500.
ARRRRGGGGHHHHH - NOW what is he going to do? He could call, the pot will be 16,000 and there will be double pot back in stacks and he's OOP - that's a bit messy. He could 4bet, but then IF YOU GO ALL IN THAT REALLY SUCKS cos 4b/call AQo for 39big blinds is pretty grim in a 8 handed game. He could fold, but he HAS SUCH A GOOD HAND. He's got a good stack, and a great starting hand and we've managed to make his life really unpleasant with a 7 and a 4 - ALL BECAUSE of the size of our stacks.
NOW. 2 orbits earlier someone opened MP and you decided to defend OJo in the SB, you flopped a Queen, he had KQ and you lost over half your stack now you only have 21,000. YOU GOTTA FOLD THAT

now and the opportunity to make a really profitable move (basically has to work like 40% of the time) has GONE.
SHOULD HAVE PROTECTED YOUR STACK YO.
*disclaimer* Am not advocating 100% preflop re-raising with