Discussion in this thread indicated that the change was made for the sake of having the ladder games move faster. It’s a shame that the potential impact on the thousands ladder players wasn’t more thoroughly considered.
The irony is that the change doesn’t really even force games to move faster, it just reduces the flexibility for players. With either a 7 day max or 3 day max (or even a 1 day max, which would be equivalent to simple timing with one day per move), a player still just has to average 1 day per turn to avoid depleting their clock (given that the +1 day/turn increment stays the same). The change only limits how much of a cushion players are given to accomodate for unexpected situations where they are occasionally away for a few days.