Gemini may be a victim here too, as TFA explains: it's Genesis that ran the scam (with DCG being Genesis' parent company).
I think the Winklevoss brothers honestly "saw" Bitcoin before most, just like they saw FaceBook before Zuckerberg stole it from them (Zuckerberg lost not just one but two lawsuits against the twins).
They may have been blinded by Genesis/DCG: just like, say, the New-York Times and Forbes got blinded by SBF / FTX.
But I don't think it's fair to say, especially while there's a lawsuit ongoing, that you "fell" for it: they are likely just victims of Genesis (and the lawsuit shall try to determine if that's the case or not).
Now they may have sold unregistered securities, but that's very different compared to downright theft (like Genesis or SBF or so many others did).
That said I'm sorry about the $13 K loss and if it's any consolation I told someone close to GFTO of BlockFi because these 8% were obviously a scam (and I don't think BlockFi was guilty: they fell for the Genesis scam) and he managed to get his 1 BTC out of BlockFi before things went south (not too sure what eventually happened to BlockFi and people who had funds there).