Yes, when I looked into this a while back I was told by the Forumer admins that gwbbcode was not supported. I have not checked recently to see if this has changed, but that is why we aren't using it. While the thought had crossed my mind about moving our forum to one that supported gwbbcode, it did not seem to be important enough to warrant a change.
Of course, if anyone spots gwbbcode running on a Forumer site or knows of a way to make it work, I am all ears. In the meantime, the closest thing we have to gwbbcode is something I created here on the forum to show the skills AND have direct links to all of them on the wiki.
EXAMPLE:
Restoration (3), Channeling (9), Soul Reaping (9 + 1). Curses (12 + 1+ 3)

Skill Code:
OAhkYkHc4ImDGzb64yD7B4QV9iB
Skill names: Splinter Weapon, Ancestor's Rage, Spirit Rift, Spiteful Spirit, Insidious Parasite, Desecrate Enchantments, Signet of Lost Souls, Flesh of my Flesh.
The coding looks like this:
Restoration (3), Channeling (9), Soul Reaping (9 + 1). Curses (12 + 1+ 3)
[url=http://guildwars.wikia.com/wiki/Splinter_Weapon][img]http://images.wikia.com/gw/images/8/8e/Splinter_Weapon.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Ancestors%27_Rage][img]http://images.wikia.com/gw/images/d/d1/Ancestors%27_Rage.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Spirit_Rift][img]http://images.wikia.com/gw/images/5/53/Spirit_Rift.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Spiteful_Spirit][img]http://images.wikia.com/gw/images/0/00/Spiteful_Spirit.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Insidious_Parasite][img]http://images.wikia.com/gw/images/4/48/Insidious_Parasite.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Desecrate_Enchantments][img]http://images.wikia.com/gw/images/0/0a/Desecrate_Enchantments.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Signet_of_Lost_Souls][img]http://images.wikia.com/gw/images/f/ff/Signet_of_Lost_Souls.jpg[/img][/url] [url=http://guildwars.wikia.com/wiki/Flesh_of_My_Flesh][img]http://images.wikia.com/gw/images/c/c3/Flesh_of_My_Flesh.jpg[/img][/url]
Skill Code: [color=cyan]OAhkYkHc4ImDGzb64yD7B4QV9iB[/color]
Skill names: Splinter Weapon, Ancestor's Rage, Spirit Rift, Spiteful Spirit, Insidious Parasite, Desecrate Enchantments, Signet of Lost Souls, Flesh of my Flesh.
As you can see, the coding is a little bit of a pain and the template code and attributes need to be listed separately. But it at least gives a visual reference to the skills and
each skill image is a functioning link to the wiki page on that skill. So while it provides all the info that people need for the build, it is more complicated to generate and doesn't have the easy scroll-over functionality of gwbbcode.
Again, if anyone knows of a way to make gwbbcode function on our forum (without violating the forum host's rules and regulations), please let me know.