Trail signs and crews consistently ask hikers to walk through mud rather than around it. The instruction runs against instinct, and the reasoning is about trail width rather than comfort.
Walking around widens the tread
A hiker stepping onto the vegetated edge to avoid water compresses the soil and kills the plants holding it. The next hiker sees bare ground and follows.
Within a season the trail is measurably wider, and the new edge is itself unstable. That edge then holds water, so the process repeats outward.
A tread that was two feet across can become a scar several times that width, all from avoiding a single wet section.
Braided trails multiply the damage
Where the ground allows, avoidance produces parallel paths rather than one wide one. Each braid is a separate line of destroyed vegetation and compacted soil.
Braiding also confuses route finding, and hikers following the wrong strand create further paths trying to rejoin the main line.
Restoring a braided section means closing and replanting several routes, which is far more work than repairing one.
The mud is a symptom of drainage failure
Persistent wet spots usually mean water is entering the tread and has nowhere to leave. The puddle marks a drainage problem, not simply a rainy week.
Crews fix it by cutting drains, building turnpike through wet ground, or setting stepping stones and puncheon so the tread sits above the water table.
Those repairs are only worth building if hikers stay on them, which is the other half of the instruction.
Timing and footwear make it easy
The reason people step around is usually footwear that cannot handle water. Boots or shoes chosen to get wet and drain remove the incentive entirely.
Gaiters help with the same problem in shallow mud, and accepting wet feet early in a day is generally easier than managing them intermittently.
Hiking a saturated trail immediately after heavy rain causes the most damage, so postponing a day where the route allows is the stronger choice.
Why this scales
Individual footsteps seem trivial, and on a quiet route they nearly are. The rule exists because popular trails receive enough traffic that behavior aggregates into landform change.
Crew capacity is limited and repair is slow, so damage created in a season can take years to undo. Prevention is the only approach that keeps pace.
Which is why the request is phrased as an absolute rather than as advice about conditions.