A spirit ranger is very dissimilar in play style and group value than:
1) bow build
2) bunker build/beasstmaster
3) trapper build
And your choice of pet can really make a difference in how you play too.
To some extent all classes can have different feels, but I find that if you line up 4 rangers vs 4 members of other classes the rangers will have the greatest variety of play.
That has led to trait optimization problems certainly but you can just get more play styles out of a ranger than most classes I find. It also causes problems within the community. If you hate spirits, you probably have to deal with a lot of rangers who love them. If you think the ranger should be all bows, realize there are a lot of rangers playing a style that is all melee.
Rangers don’t lack build diversity. We lack the ability to optimize all that diversity.