Taxodermic Owlbear has assembled an impressive list of retroclones. (Though I might nitpick that only a few are technically retroclones.)
It is periodically asked if we need another clone or D&D knock-off. Rhetorically, since you only ask that if you think the answer is “no, we already have too many”.
But consider the passion and imagination that that list reflects. Very few of those games made anyone a living, and even people who write RPGs for a living don’t do it because it is anything close to lucrative. That list is proof to me that the traditional RPG hobby can have a life beyond the RPG industry.
And I think it is great that all those games can leverage a time-tested core while adding just a few or a lot of unique spins.
Some may say that that passion and imagination would be better channeled into other things. e.g. adventures or games with more originality. I say that telling someone what they should do with their passion and imagination is the quickest way to kill it.
Do we need another clone? Yes, I think we do. We need people to follow their individual muses and inspire us with the results.