Doing it because you have always done it

Continuity is a real reason, but it should be named rather than disguised.

There is a particular flavour of answer that comes up when you ask why a thing is done a certain way. Not a justification but a shrug: this is how it goes, this is what we do, we have always done it on a Thursday. Sometimes that answer conceals a good reason that nobody remembers, and dismantling the arrangement will reveal it painfully. Sometimes it conceals nothing at all. The trouble is that from the inside these two cases feel identical, and the shrug is offered with the same confidence either way.

It is worth separating two different things that hide behind the shrug. The first is genuine continuity value: the practice matters because it has been done for a long time, and the duration is itself the point. That is a legitimate reason and it should be stated openly rather than dressed up as practicality, because once it is stated it can be weighed honestly against the cost. The second is pure inertia, where nobody prefers the arrangement and nobody has revisited it. That deserves no protection whatsoever, and usually collapses the moment somebody asks about it plainly.

The useful question is not whether the practice is old but whether anybody would choose it now. Imagine arriving fresh into the situation with no history and being asked to design the arrangement. If you would land somewhere close to what exists, the practice has earned its place. If you would not go anywhere near it, then what you have is a fossil, and it is being maintained by nothing more than the difficulty of being the person who suggests otherwise.