That would make sense if you knew how hard things were going to be and if you could predict external responsibilities.

For example if I plan to meet a friend tomorrow, but tonight my child unexpectedly gets sick, I can call the friend and say, "Sorry my child got sick. How about next week?"

That might happen multiple weeks in a row, but eventually (assuming a patient friend) we'll get together and renew our connection. On the other hand, if I played it safe, and said, "I'm too busy for friendships now that I'm a parent," we would both have less friend-time.