I noticed this also and I have a woodworker at the same level and noticed that those weapons have non-common damage on clubs/hammers and bows. Also the mini instruments at level 70 have non-common damage types on them.
So basically my conclusion is for some reason the metal weapons (weaponsmith) have a lot more instances where the damage type is common than the other professions.
I would also /sign as wanting to know if this is an oversight or WAI
I have a theroy. The two highest damage dealers that would use a sword (offhand) are loremasters and champs. For example, my lm has over 1k of will giving her 11k of melee damage. Common damage dealt will be reduced as most mobs displell 40% or more of common damage. So it follows the choice of common acts as balance.
I doubt that (or at least HOPE it isn't that). I can't speak for LM's, but as a Champ, I can wield various weapons in my off-hand. I just prefer swords. If this isn't fixed by the time I get there (I level fairly slowly), I'll have to use the Beleriand Axe I suppose. I'm hoping this is just a bug and they will put Beleriand damage (or better yet, let the crafter pick what type via the multi-output!) back on the sword where it belongs. :-)
Just checked in game, and you are correct, the Dagger has Beleriand damage on ONE of its two multi-output options. Either I missed that originally, or they added it after my original post. In either case, thank you for pointing that out. That's a step in the right direction.
Still, they need to either add that to the Sword as an option as well, or better yet, put it on all outputs of the guild weapons. As others have said, a max-level, max-reputation GUILD weapon should not be doing Common damage. At the very least, each weapon should have at least one option to have Beleriand damage (like the dagger) or do Beleriand damage on all options (like the axe).
Either way, this still reeks of being an unfixed bug.