Everybody loves the new strongly typed languges coming out.

The crux of the issue is in hiring and training costs. When you measure how great these costs are against the potential benefits it becomes less attractive, this is doubly so for small/mid sized companies who really, have no good reason to switch to a strongly typed language.

Additionally, Java -> kotlin poses less gains considering Java already has some level of typing. Javascript -> Typescript poses much greater gains consdering Javascript is always flying by the seat of it's pants.