I also have some coins on yobit. So what have I to do with them now? For what reason Yobit didn't support a swap? Usually they did it. For example, they provided swap of PACcoin recently. Do you mean that all of GEO coins remaining on Yobit exchange cost nothing now?
Ask Yobit, pre-swap there were numerous requests by Geo developers to the exchanges - Bittrex, Cryptopia, Yobit for the swap support. Yobit did not reply and kept the old market; since it's their website they can do whatever they like. Meanwhile Geo devs announced that Yobit coins are obsolete as they were not transfered to the new blockchain.
All coins are worth what others are willing to pay for it, maybe somebody sees value in an old blockchain without developer.