It's just an opener. And opener doesn't matter. What matter is how you play the rest of the match.
Generally, the clap is good because it provide 2 grips instantly and can makes you easily manipulate your opponents in lower tiers. However, there's much more to learn than just a few openers

An opener is an opener. And you can counter every opener. And most experienced players will noob clap in order to put themselves in a position to where the opponent can not have a free hand to decap or save themselves. It also makes lifting easier.

I don't think you guys understand why it's called noob clapping. It's not because only noobs use it. It's because it requires so little skill to use that loads of noobs end up doing it. The follow up is an entirely different question.

This is also the reason some people don't like it. It doesn't show any skill and while it is a legit strat, it's like the noob tube in cod4 where you can just shoot it off and get kills without much precise aiming.

I think most of the controversy around double clapping is how most new players do it anyways.
Like, I've been guilty of using a double grip instantly in the first few turns of Aikido matches before, but it was never straight up. I would try to transition from a punch or kick into a double grip to transition into a Takedown, throw, etc. - If that makes sense.

I wouldn't call it legit or a strategy, because most players who use it only use it solely for the purpose of attempting to end the match with the one opener. High level matches(at-least in my opinion) should be going off into free-form fighting, kicks, punches, etc that try to counter each other and eventually wait for someone to slip up. Either into a decap, dm, or dq.
But then there's the one-shot one-kill styles used in shorter matches like Taekkyon or something that are short because of the way the mod is.

That's just my '11 player opinion though and is probably not too relevant anymore.

I see more noob's do complicated youtube kick moves than noob claps, most noob's don't even noob clap.

thats because they dont know what to do after. The youtube kicks give them a step by step way to win the game (generally speaking) like Text said the only reason its called the noob clap is because it uses as little as 2 joints so its not hard what so ever to do

Regardless of any arguments, getting uppity about a move and trying to single others out for using it is both a waste of time and pointless. The simple fact of the matter is, this game is competitive at its core (assuming you're playing with randoms) and clapping is a very versatile and effective move, for aikido anyway. In judo idk, but I can tell you not many higher level players will ever clap in a judo duel.
If you want a counter, claps are hard countered by kicks.

Or, after 15000 games you still use the most simple move.

I look at belt as experience you play 15000 or 20000 games I am 100% sure you know more moves than the noob clap.

But you can buy qi? Thus negating the overall experience quota. And of course Swaves knows more moves. But that doesn't mean he needs to do complicated openers to win.

Man! I noob clap all the time. The only difference is that I relax all, bend the knees, contract the wrists, extend the elbows, and flex my glutes! Noob clap is a fundamental opener to all decent grapplers. It's a good start to becoming a great toribasher. But, haters gunna hate!