Or the regular fighter that gets Punishing Charge (Encounter 1), which damages every enemy that takes an OA against you equal to con and does 1[W]+strength+con damage.
Oh and did you forget about threatening rush, which is a fighter at-will you can use as a melee basic attack when charging? Not to mention it handily marks each creature adjacent to you at the end of the charge. So your statement isn't even true.
Dude, seriously, these are some pretty petty corner-cases. Comparing the Knight (for whom we know 2-3 powers) vs specific builds with specific powers?
Look, if a Knight gets Dazed, then... he's actually really well off, because he is probably already
in a stance, and he is getting all sorts of benefits to his melee basic attacks by default, and can still trigger his free action encounter boosts, and he probably already has defender aura up and is doing perfectly fine at marking people.
And, as mentioned, likely better on a charge than the regular fighter stuck with his basics. Yes, the fighter could have taken some very specific powers you can use on a charge. Will most fighters take those powers? No, and it is silly to imply that they do.
In any case, assuming the Knight will regularly spend combats dazed is about as reasonable as assuming all Fighters will regularly spend combats immobilized. Sure, it might happen, but very, very rarely and isn't worth declaring a build useless because of it.
Especially when the hypotheticals you've stacked against the Knight are really not that big a deal for him. "Oh no, I'm stuck doing extra damage with all my attacks." "Oh no, I'm stuck hurting multiple enemies when I charge."
Does being dazed limit his versatility? Yes. But, like the regular fighter, it honestly causes far fewer problems for him than for most classes. Other defenders, like the Paladin, will have trouble marking while dazed. Striker's won't be able to curse/quarry enemies, or lose the mobility to get into position, or can't flank to deliver sneak attacks. Leaders can't use their healing word and attack.
I mean, I'm pretty sure the Knight comes out ahead of 90% of the classes in the game for how effective he is while dazed. And when we see the full details of the class, I wouldn't be surprised if he comes out ahead of the regular fighter, as well.