I honestly don't know, I think that many of them have just been exposed to a new typed language and this makes it exciting. I've been programming for a very long time, and this seems to go in cycles. There was a time when untyped languages (Visual Basic for example) were flamed for being so crappy, because powerful languages like C/C++ were typed.

Then came PHP and showed us that it's not necessary to have types. Then Python and Ruby came into the picture, people loved them, then eventually typed languages like Go got traction, typescript, rust, etc. Rinse and repeat.

For libraries, typescript is awesome though, it makes it very easy to understand how a library works.

The thing though, is that types (and constants) in compiled languages behave extremely differently on an efficiency and compiler level than in TS (I know this is not as important as it used to be, but still is nevertheless).

Many people have no clue what happening under the hood. Obviously the node (V8) engine is extremely well optimized.