I'm gonna try to explain KOE 18 for a second here.
He's saying if you do JIK, it yeilds the same results as a JIP, as in... you get to do whatever you want if they block.
But if all you're ever using is JIK.
Eventually if they know they can get out of it by just naked ducking and eating the kick. thus making a wake up game.
You open up a whole new game that wasn't there to begin with with you only doing JIP.
Of course theya re never gonna let go of block if you just JIP.
But with JIK, they might think about it if they know what dizzy talked about is an option. and if they go for that...
that opens up JIP to be confirmed into 1,1 spear if you change to JIP next time.
If you keep JIK, you still get pressure. and if they are like "Well I really don't want to be pressured this time" They will naked crouch. (which opens them up for JIP.)
And they can't just stand up and take the DJIK, because it leads to a combo at no risk.
There really isn't a reason I can see to NOT do it. at the very LEAST, you open them up JIP in the future. At the risk of possibly losing your guaranteed pressure/advantage to a wake up game.
If they ONLY BLOCK EVERY TIME. then of course both options aren't really that different.
It's just the options that open up for your opponent off deep JIK, will make them change behavior.
it's just an option I see.
If I'm wrong on anything let me know.