TL Mafia 'Area' LIII

http://www.youtube.com/watch?v=I5kSNwYUx5o

we know for sure that his destructo-disk can cut ANYTHING. It can't be blocked. you see it cut through mountains, planets, etc. Now, it isn't the fastest attack-- in fact it uses most of his energy and is fairly slow. Typically what happens is Krillin is getting his ass kicked by some bad guy then he's like "ok i'm using destructo disk" and the bad guy is generall some Muscle (not the head honcho) and is like "pshaw I can c atch whatever you throw" and krillin is like "ok catch this" and then the bad guy is getting all ready to BLOCK the unblockable attack-- cause it's a secret attack and he doesn't know it'll kill him. But then the boss is like "NO DONT BLOCK IT, DODGE IT!" and then he dodges it and it cuts through a mountain behind him or something and they're like "oh shot Krillin isn't useless" except he IS because he just used his one attack, and he's out of energy and it wouldn't work a second time anyways.

Now, this all seems pretty reasonable but there are a few problems that immediately become apparent with even the slightest application of critical thought.

ONE: how is Krillin the only guy who ever uses this ability? it's not like it's something only he should be capable of doing right? Like he's just a regular human. Goku should learn it or something. Or maybe it's something secret or only unique to Krillin right? But this segways into
TWO: Seriously, how is Krillin the only guy who uses destructodisks? Clearly bad guys are like "oh we shoudl dodge this instead of blocking it" so they've SEEN it before. It's the only attack that CANT be blocked. Even Goku's episodes-long-charging spirit bomb can be blocked, but NOT THE DESTRUCTODISK. Like, how can you recognize this attack if you haven't seen it before?
"Oh but Blazinghandl clearly it moves too slow, they just dodge it, etc"
NO YOU'RE SO WRONG look ok so Krillin's other thing he does a lot is "Solar Flare" right? Basically when shit goes bad (As it always does for Krillin cause he's a weakling) he uses this Solar Flare, and it briefly stuns his opponent (for like 20ish seconds) and Krillin uses this opportunity to escape. He teaches it to his bros Goku and Gohan (who apparently can learn this even though they can't learn destructodisk). bUT THE MAIN POINT is that he has this ability. But, if you think about it, an ability that uses no spirit energy stuns your opponent for a moderate amoutn of time is the most advantageous technique you could possibly know if you use Destructodisk. Whenever Krillin stuns the main victim to get away, he should just fucking cut the guy in half with a destructodisk while the guy spends like 30 seconds clutching his eyeballs.
Literally every person in DBZ except Piccolo (and Cell who has Piccolo's regenerative ability) could be defeated in like 10 seconds by Krillin in this fashion. In fact, almost every person in DBZ gets solar-flared by him (or hell, a friend of his when he's nearby) at some point! Krillin could be the strongest guy!

But no, NO that would make WAY TOO MUCH SENSE