I would phrase it like this: It is a good enough alternative to the reference implementation and Luke has sufficient reputational history to run a project like this.
Does anyone has more information about what else is going on here? I don't see such discussions in bitcointalk forum
There are good social reasons for its existence. At least one good alternative should always exist. Otherwise we risk getting into a "king in the high castle" situation where the developers do primarily what they want, and they very rarely try to communicate with normal users. That said, Luke also has weird
stancesviews on many things
are that doeswhich do not help at all.
If I recall correctly once he even advocated for lowering the block size. 