No, it can't.
You're choosing to show some highlights and overlook the typical - and even those really don't make your case.
Clearly I'm not. These highlights are taken from the best at what they do. Miguel Cotto is the undefeated Welterweight Champion of the world. He is anything but typical. Rumino Sato, although retired, was one of the greatest MMA submission specialists ever. He consistently submitted people faster than any other grappler in MMA, then or now. Mirko "Crocop" is possesses the most powerful kick ever tested. None of these guys are typical. Neither is any of the things they can do.
The spectacular "I've only seen that in demonstrations!" finishes might look cool, but in MMA they're the exception, not the rule - for every fight ended with a flying armbar, there's fifty fights in which a guy tried 5 or 6 times to sink an armbar before he finally got it.
Not true. I've trained at Beverly Hills jujistu when Bas Rutten, Mark Kerr, and Oleg Taktarov were all trainers. If someone fails three times they're not going to sink an armbar. What's going to happen is they're going to try and fail repeatedly and face a decision with only a string of failed submissions. The reasons are numerous. When you attempt a submission local muscle fatigue sets in quickly (in about 5-10 seconds). Fatigue to worked areas increases bloodflow and body temp causing sweat. Sweat alone makes it difficult to sink a sub but sweat and fatigue makes it nearly impossible. This (among others) is one of the reasons for adding additional submissions to a fighter's arsenal (of Daily and Encounter Powers).
You're basically just choosing to call whatever ends the fight a "Daily", and ignoring the fact that most of these people will be doing their "Daily" multiple times per round, until they land the big one - which doesn't make it a "reliable" Daily ability either, it just makes it the equivalent of an at-will that resulted in a critical.
Actually I'm not ignoring anything but I'm glad I got you using 4e terms to explain the situation

Since we're using 4e terms now, you're ignoring the fact that a Daily Power does at least three times as much damage while simultaneously providing a lasting effect. Using it repeatedly until it lands is exactly what Reliable means. If Crocops highkick lands and doesn't KO the fight usually goes to a decision - fact. Tyson lost when his KO uppercut wouldn't land (Holyfield, Douglas, Williams).
What happened when Bernard Hopkins landed his infamous right counter-punch against Calzaghe? He knocked him down. He also never landed it again and lost.
What happened when Taylor counter-punched Pavlik with his lightning fast hook in round two? He staggered him badly. Then proceeded to expend all of his Action Points, Dailies and Enc powers. Five rounds later Pavlik staggers Taylor with his "Ghost of Tommy Hearns" straight right Daily and unloads his Enc arsenal to KO him in the seventh.
Attacking and landing an At Will won't finish the fight in most situations, even if it's a critical. It will register as a "Power Punch" if the damage is substantial enough. Which brings up the question - How do we determine whether or no a maritial exploit is ordinary or extraordinary (enc/daily)? The effect.
Most of the time, it's got more to do with luck than skill - fighters do the same thing over and over because it chips away at the enemy and they know that if they execute it well and patiently, they'll eventually be rewared when it lands flush.
It's pretty much the antithesis of focusing all your energy on the one big attack that you know will end the fight for you.
I've trained in Muay Thai at HITS in Citrus Heights where we would cross train with THE Pit (Liddel's Gym). I've boxed in the Marines. You're talking about the real world, not D&D. So we're not rolling dice anymore. Lucky shots don't exist in the real world. If you try it and it succeeds then luck was not a factor, it was skill. When skill is inadequate all of the luck in the world won't save you. Skill will provide you with the strength, speed, technique, and coordination to properly execute your manuever. Lacking in skill against a skilled opponent will result in a one-sided thrashing.
[ame="http://www.youtube.com/watch?v=EAaM_RyCZDM"]The One-Sided Thrashing of Undefeated KO Artist Gary Lockett[/ame]
[ame="http://www.youtube.com/watch?v=4tdQUi4gIog"]The One-Sided Thrasing of Contender Star Alfonso Gomez[/ame]
Both Cotto and Pavlik are undefeated champs. Both fought contenders with far less skill. Both ended the fight early and walked away without a mark. In D&D terms, with all of the punches thrown one of the contenders would have rolled a 20. However, any twenties rolled were not done so with an Encounter Power or Daily Power. Furthermore, as high level fighters Pavlik and Cotto have access to more Utility powers that allow the to negate attacks. They negated their Encounter Powers and Daily Powers then outworked the lower level fighters.