One of the reasons might be that they realized that the absense of an official LSP for Kotlin will hinder its wide adoption by new developers who want to try Kotlin but don't want to move away from their favorite IDEs.
>I know it's a difficult spot because such effort will also indirectly compete with their main product which is an IDE, so I'm not very optimistic it'll last.
I would say this if this step was taking early while Kotlin is still a new language in the market, but I think their late decision to develop an official LSP for Kotlin is because of reasons you just mentioned, but maybe they changed their minds because they saw other benifits including a wide adoption of Kotlin.
This is horrible for people who learn languages using TV Shows and Movies. One of the most frustrating things I've encountered while learning German is the "paraphrase" thing, it makes practicing listening very hard, because my purpose wasn't to understand what was being said, but rather familiarizing my ear with spoken German.
So, knowing exactly the words being said is of utter importance.