In 1v1s, disarms can usually be countered by rewielding, and polearms are difficult to disarm and may just give me 2 more rounds with which to attack the enemy. Never really had a problem with orcs or normal disarmers, the only issue I had was with the strip skill which can disarm and place the weapon in the stripper's inventory. In fact I killed Zugnu 2 or 3 times I think (but fled more times than that).
In fact, wielding a disarmable weapon in 1v1 situations is a kind of baiting, it makes the opponent think they've got a chance to kill you if they time a clutch disarm. That's exactly what I want them to think.
You really don't want to make a build which the enemy thinks "well I can't do anything to you, I've got 0 chance at all". I definitely had this problem with my dark-elf sword spec. Some enemies had pretty much 0 chance against me when I was decked, but they sure as hell didn't even bother to fight me 1v1. PK is not about building an invincible juggernaut.
You want a build which technically they can overcome with the right tactics, AND if you make noob mistakes (but you will not). And you want a build which can seal the deal on unwilling participants. The most ideal version being a build that can sneak up on an enemy unseen, and bring him from 100% to 0% with high probability (assassin with martial trance or 100% assassinate for enemies with Word).
In gangs, disarm would be a problem. But a giant warrior isn't really designed to face 1vX situations, I shouldn't be fighting those fights at all unless there's one "soft" target I can take out with a good 600 hp drum or something.
If an Anathema-happy Emperor is around and may boot me for not turning up to face a gang, I quaff a spiderhands prep and enough damage reduction to make death-by-lag or death-by-burst unlikely.
Also there's Khalghaver's Bane, Fordurn, mace of (element), which are not disarmable. If I had no spiderhands and had to face a gang with a disarm plan, I could dual wield maces with a noremove mainhand.