Although we're advice not to feed the trolls but here's what i have to say concerning this issue. Is yobit a shady exchanges, yes but is Cryptotalk a shady forum? Maybe, maybe not. We have no proof yet so we can't conclude. From the look of things, it seems the only associated between the two projects is that cryptotalk is using Yobit panel as a management platform. Now until that is proven otherwise we can judge Cryptotalk based on the reputable of yobit.
Concerning @Yahoo's association with the project through management, this has been debated on and it's better that way than the previous of leaving any campaigns requiring high number of post which will definitely result to spamming to operate unmoderated.
Like others said there's no active scam accusation against Yobit. They have made bad decisions in past advertising campaigns on this forum, and have paid the price. However, they have made the step in the right direction, and those that are claiming "Yobit does what it wants" obviously isn't true if they've resorted to using a campaign manager, and a reputable at that. It was obvious that they tried to save as much money as possible, and thought they could brute force their way into Bitcointalk. Which obviously didn't work out for them, and in return they had their signature banned from the forum.
Even if you were to judge Cryptotalk based on the existing reputation of Yobit. It hasn't been confirmed that they have scammed anyone, and the only real criticism you can say about them is regarding the whole Yobit spam, but they're at least making steps in the right direction. I haven't used Yobit, because I don't really have a need for an exchange, and I don't deal in altcoins. However, if I ever did I'd probably remember them just from the shenanigans that have happened. Would I like them to make a little more effort, and place more restrictions on who can enter into their campaign? Yes, probably. However, at the moment I haven't seen too many spammers on the Yobit signature campaign, and for those that are will hopefully be removed shortly by Yahoo. Despite their history on the forum, everyone knows about them, and with an effective strategy for the existing campaign every new comer into Bitcoin will likely hear about them. I wouldn't be surprised if they're the go to option in the future just because of the amount of exposure they seem to be able to get.