I understand the frustration but what are we to expect when Square announced 3 different titles for 3 different platforms back in 2007?
They sent the series from "fairly popular with great potential" to "niche series that only hardcore fans will follow and we'll grab what we can from each platform".
I have no idea which idiot thought that was in any way a good way to propel the franchise forward.
So people (die-hards as well - including myself) got disappointed and since the games didn't seem to be as important* as KH3 in both story and scale, they got ignored.
* I know the importance of all 3 titles. Aside from BBS - which is mighty important, re:coded is filler whose purposeful story can be summed up in 3-4 scenes (you are lying if you say otherwise) and 358/2 Days, while having a great story that fleshes out Roxas and Co exists simply because they "needed another handheld title", so they retconned another character in just to create a game.
I've said it before.. the KH brand has taken the most damage because of Square's mismanagement in the last decade and beyond. And KH3 might just be the game that takes the fall