The only reason is autocompletion really, so not as much "hidden" as aiming to prevent stumbling into task.escalate(...) and go "uuu, tempting, let's do that" when I was about to write await task.value which will do the escalation in a much better way (with dependency tracking "who is waiting for this").
It's not a strong take though, and we can move to instance methods if we'd prefer that.
So while this may cause some suboptimal behavior it would not prevent the dependency tracking done by the await... So it's not the end of the world if someone did that. We'll highlight this in documentation. People can always do the wrong thing anyway if they're determined enough 
For the sake of completeness, there was a discussion about this in the pitch: