My tanks have bow as the secondary weapon for AOE use against dungeon mobs in PVE when there is no boss around.

I like to use Bombard (morph of Arrow Spray) to immobilize all targets in the mob so the DD's can do maximum damage without having to chase them (or run away from them). For stronger mobs with healers and archers on the outside, I do this as we approach and then swap to sword and board for melee/single target attacks.

Seems to work for me and I get no complaints.

I use bow for both PVE and PVP and it serves different purposes;

for PVE:

1. Bow is on back bar. Used for setting up DOTS such as poison injection + volley. I also located some of my buff skills here on this bar --> rearming trap, igneous/molten weapons etc.
2. During certain fights, there are mechanics that dont allow (or make it very difficult) to melee DPS. Ie: engin guardian or last boss FG --> in those cases I slot snipe and molten weapons to weave heavy attacks with snipe + poison inject + volley as ranged DPS

For PvP:

1. Bow provides major expedition for immobile classes such as my stamplar and stamDK. Saved my life many a time with dodge roll move speed bonus.
2. Bow provides insane lockdown against opponents --> bombard OP
3. Bow provides Snipe for huge stealth openers.
4. Bow bar is used to contain certain buffs for me such as shuffle and wings/molten etc.

Basically I use bow because of the utility, burst and flexibility it provides. Melee weapons are all about damage and normally dont provide any reliable CC or move speed short of WB... Just look at DW lol. It has almost 0 utility other than aoe damage reduction which no one bothers to slot.