Beating a dead horse but stop looking at reasons for why Kaiten was ever removed to make life better for the players or improve our experience of the game, only some SE drone seriously think that. It was removed purely because it was a an annoying abbilities for the dev to work around right now with auto crit balance and in the future for new abbilities.

This is why everyones playing sam was baffled to learn it was removed at first and why they couldn't ever come up with a good sounding excuse or argument for the removal and now dodge the subject entirely, they know with time more and more peoples will forget or not even know about it anyway.