The check-down move is usually only done in a tourney when:
1. Eliminating a player significantly increases the pay-out to the remaining players.
2. The amount of chips at stake is insignifant compared to the increase in pay-out.
3. Neither player has a very strong hand.
4. The sidepot is either "dry" (empty) or very small.

This produces a situation where it makes sense for players to try to increase the chances of eliminating another player. The only way to increase the chances of eliminating an all-in player is to check the hand down so that the all-in player has to showdown against multiple hands that could have produced a winner by the river.

Also note that AFAIK you are not supposed to talk to the other player about checking a hand down when you make this play in a tournament because then it can then be considered collusion.