In a PvP server, getting killed out in the world and having Wisp is actually quite useful.
On that note, getting back to your corpse quicker is nice. While yes it's only active when you're dead, it still means you get back quicker then others.
This. Whip Form was perhaps my most favorite racial back when I was on Darkspear. You'd be surprised how many times I could pop back sooner than they'd expect and get revenge!
Somehow I suspect it's more about dumb campers being unattentive. I doubt they saw you pop up and said "hey we weren't expecting you for like another 15 seconds! We got owned by whisp form."