Comment by cortesoft

Yeah, this was my first thought...I am guessing the author has never accidentally pushed out a bad DNS entry and needed to revert/update.

Everyone probably starts with higher TTLs, then the first time they mess up an update they switch to a short one.

The author seems to not appreciate how big a problem a misconfigured, long TTL DNS entry could be for someone.

Other reasons for short TTLs... maybe an IP gets blocked/flagged by a large network and they need to change fast... or a network path is slow and they need to move to a new location.