The Turkish government has denied the Armenian genocide for a very long time, even though it is a real incident in human history. Simply denying the truth about the Armenian genocide, even if it hurts the Turkish government, does not make a person a terrorist, they simply recognize the truth.
Obviously he believes that everyone who disagrees with him is a terrorist but that does not make it so. Several scholars agree that the Armenians were completely innocent and were slaughtered based on hatred and not because they posed any realistic threat to anyone. He would deem anyone a terrorist who doesn't subscribe to his views.
The parliament members who backed this motion are definitely not terrorists. The Turkish president and those opposing the motion are closer to terrorists in this case. As for the "impure blood" remark, I don't even know what that means. The motion's purpose is just to admit wrongdoing and pay respect to innocent people who lost their lives. That's not even remotely close to or related to terrorism.
He's just mad he got called out on his racist actions. Why is it allowable to slaughter some people but not others? History may be written by the victors, but that does not mean the losers are forgotten. And like Stephen King once wrote, sometimes they come back. Wouldn't you agree?