Sure, I can explain.
First, to clarify that I understand you, you're arguing that every other class is better than 2H'ers. That's absolutely true under certain battlefield conditions , and absolutely false under certain conditions. We could probably argue as to what these are, fairly, but we'll stick with the obvious extremes- 2H'ers are weak in open fields and amazing with abundant sources of cover or in some tight spaces. The only ones they're very strong against in open fields are shielders, which are slower (foot and swing speed), and you say that have decent reach when in reality, their reach is worst of all archtypes. When they get into swinging distance, 2H'ers have the best damage, the best weapon abilities (crushtrough, for instance), and the second best reach (dividing cavalry into 2H, 1H, and Polearm, the latter being the vast majority). When it comes to pure melee power, 2H'ers stand supreme. The scoreboards reflect this.
An easy way to verify this is to look at siege maps. Who always tops the defender's scoreboard? 2H'ers. Not even ranged folks, being in virtually ideal conditions for their class, beat them with any frequency (I've seen some get close from time to time, but never beat them outright). Yet on offense, 2H'ers (and ranged) don't do nearly as well, usually because they lack any cover until they break through and take the wall. Only shield infantry outshine them, for obvious reasons.
I'd like to break down the other classes as well, where 2H'ers beat them and where they beat 2H'ers, but this really is a long, long discussion and it's after 4am. Maybe tomorrow. If anyone else wants to jump on it, feel free to. Your argument simply doesn't stand and the scoreboards reflect that consistently. 2H'ers are a very viable class with major benefits and equally major flaws. They dominate certain classes in certain cases, and they get dominated by certain classes in those very same situations.
This is all quite far from the original post, however. The only point that has to be reiterated is that, yes, 2H'ers should fear ranged, shields should fear axes, horsemen should fear pikes, ranged should fear shielders* (goddamn huscarls), and peasants should fear everything.
*Looking back, you seem to emphasize the point that ranged can easily shoot above, beside, or under shields. That really just isn't the case. I've poured hundreds of arrows into shields, trying to pierce (oh, wait, slashnerf, ugh, what?) that little toe and rarely with any effect, even when it's clearly unprotected. Really, maybe a dozen times out of HUNDREDS of attempts. The forcefield effect with even just 3 or so points in shield is truly amazing. I've never gotten a headshot on anyone while the shield was raised.
If you have 3 shield skill, you're obviously not a 2h player but a shielder with some 2h so that's invalidated.
2h doesn't "beat" 1h. 2h requires skill, timing, and precision to manual block while 1h has an AUTOBLOCK feature, most shielders wear huscarls, not kite shields, so good luck "breaking" their shield. You would have to block at least 12-15 times with most swords to break a shield, a feat 99% of the cRPG population cannot do.
1h reach is even longer here than it is in native and 1h+shield vs 2h is still even in native. In regards to your "range" argument, a 2h must backpedal while a shielder runs at them, shielding, and backpedalling is slower than walking forward so a 2h will get 1, maybe 2 swings off (on an auotblocking shielder) then the shielder is inside with extremely fast attack speed and good damage (once again, my example of losing half my hp to a 1h with 7 IF, 21 STR and full plate you didn't address), so while you can say that "2h'ers rule the boards" in public matches with bad players, sure, you have some validity in that decent 2h'ers will destroy bad players who can't block. I'm talking about the competitive end where people actually know how to play, 2h'ers don't have any area where they shine. The only time they shine is that they are able to capitalize more quickly when a player is bad.