There are two reasons for this. The first is that man is not omniscient, and therefore all our actions have unforeseeable consequences. Tradition, the inherited wisdom of the race, is simply the accumulation of the wisdom of individuals. The past dies when its heirs fail to increase it. It is futile and pointless simply to try to preserve the status quo, which is always doomed, sooner or later, to go the way of all mortal things.
Innovations strengthen the established order by adapting it to changing circumstances.
On the other hand, tradition and order are needed to consolidate and preserve past accomplishments. Innovations are only enduring when integrated into an established order. No matter how desirable any reform may be, the preservation of social order and the rule of law must always have greater priority. Given this basic stability and continuity, one may effect gradual and prudent reforms, as necessary. It is a basic requirement of human action to have stable and predictable social conditions.