I have to agree with you about that. Things could change and forge or mcp or both could vanish and people would be stuck. But, after the whole bukkit situation especially, I think there’s a pretty decent chance that they’d at least pass on the project to someone else, if not open source it if it isn’t already.
And at the moment, Sponge does have plans to be forgeless and support glowstone as shown here. Of course that’s in the future and things could change but at least there are plans to make it independent. Oops @Owexz ninja posted while I was typing this hahaha.
Also as for why it’s taking so long, as @OffLuffy showed already planning the api will will take up a bunch of time.