They're only really crazy vs. some 2h in that the mid to mid-long axes have bonus vs. shield + they're balanced so they're very flexible, but that's compensated by lower effective length with the attack animations.
Don't get me wrong, Long Axe is very good, but it's not all that crazy compared to 2hs near the same cost unless glitchy hiltslash/feint animations are used, and that's not really restricted to a specific polearm. Plus if you're not fighting someone with a shield, you usually give up some sort of trade-off via range/effective damage/speed/being able to rear. (See Bec-De-Corbin or the Hafted Blades vs Long Axe/Long War Axe/Great Long Axe, Miaodao or 2H Warhammer pierce mode vs most of the 2H axes, etc.)
Just remember that:
1) You don't necessarily have to smash a shielder's shield to kill them with timed swings/chambers. Trying to smash shields is actually a bad idea vs. very high AGI shielders(~27+), as they can hit you in between a missed swing or if they force a glance.
2) You can bring more than one weapon. Fast shield smashing weapons are very cheap for 1h or 2h players, so you can bring something that's better than an axe vs. non-shielders like a Miaodao, since there seem to be a lot of 2h/shield-less pole users with the demise of the super-ranged meta.
I wouldn't be against having more slow, unbalanced large base damage weapons, they tend to be very satisfying on hits. The problem is it wouldn't make that much sense with the current polearm models within the ~115-140ish range unless you made all of the 2h weapons within the ~110+ range slower and beefier.
Another problem is that while I personally suck at manual blocking, the average skill/reflex level of people who have been playing for a while is high enough to duel to a standstill over several minutes using really fast weapons with really high WPF.