> unless you're hiking in dangerous wilderness, there is no hard reason to prefer larger numbers.
This is simply untrue. Many people hike in groups because it is drastically safer than hiking solo. There are plenty of stories where separated hikers simply disappear after going off-trail in thick brush to use the restroom. THIS is the primary reason why the stigma exists and the author completely brushes it aside.
If you're a person hiking in "non-dangerous" wilderness you probably need the group even more since you likely failed to bring a map and compass, much less any survival gear. You may very well not know which trail you're on nor have planned for features and junctions to expect. The bare minimum you can do is stay with a few extra people who can help carry you out when you sprain your ankle or worse.