Last Guy in the Airlock
This is not my experience either. What evidence do you have for this claim? I find it surprising.No, it is not common. Like, at all.
Most players of a martial class do not dip into magic abilities.
I would have though a Nature Cleric would also benefit, who does not even need feats or multiclassing to take advantage.The only non-Druid character who can really benefit from Shillelagh is the Monk.
With feats, it also allows effective builds such as a Wisdom-focused Ranger, which does not seem that unusual.