Chirine Ka Bal acknowledged that this was known to the Tekumel Foundation in Barker's lifetime by some of his peers, and after his death by even more. While I can understand not knowing how to deal with something like this, the fact is that an attempt was not even made.
That having been said, I bought some Tekumel stuff after their announcement because I didn't have any, I wasn't sure if it would continue to be available, and they had pledged to contribute to organizations working to oppose and correct attitudes and misinformation like Barker's.
I appreciate Tekumel, while having no respect for its creator or his views. Tekumel has always been a niche product with a pretty high buy-in for the player. These days, I prefer more width than depth, so Talislanta wins over Tekumel. But there's no denying that Tekumel is awe-inspiring and unique among RPGs.
Still, as a commercial concern, I think Barker's anti-Semitism, and the Foundation's cover-up of same, have put the nail in Tekumel's coffin as anything more than a sad footnote in gaming history (not that it was doing big sales numbers anyway). To be honest, I'm not sure that this could have been avoided even if they had been proactive in acknowledging and denouncing Barker's ideology. There would have been questions about who knew what, and when. There's really no coming back from this. That would be like OJ Simpson or Phil Spector getting their reputations back. It's just not gonna happen.
Some will separate the art from the artist. Some will be unable or unwilling to do so, and will leave Tekumel behind forever. I know my regular group, ranging in age from mid-twenties to mid-fifties, would absolutely not play this if I proposed it, due to Barker's views. I bought it, I'm certainly in no position to judge anyone, and I'm not. I just think that this scandal has effectively killed Tekumel, at least insofar as attracting new players. It's a shame, but these things happen.