So, I take it you are of Armenian decent? The thing is, this is a pet issue. I won't argue whether or not it should be, but genocide happens, and generally people don't care, as long as it's sufficiently difficult to do so. It's very easy to call out your enemies for genocide; indeed it's a realpolitik advantage for your when your enemies do it, as you can lambast them for it, and gives you a reasonable casus belli for regional intervention. If you are a strategic ally, however, it doesn't quite work that way. The U.S. needs Turkey as a hedge against Russia and Iran, and Syria. It is fairly likely that the U.S. would lose regional influence, and less importantly from a strategic perspective, people would die as a result of the deterioration of the relationship. Having Turkey admit culpability will not bring the people killed back. What is the best case scenario for the results of ostracizing Turkey? A partition resulting in U.S. Aligned states in turkeys's east? Those have limited strategic advantage, you'd lose control of the Bosphous, and the problem of various pillaging bands in the Levant would get worse, not better, as the powers that be in Istanbul more heavily subsidized ISIL forces.
You can be mad you were lied to, but you were hoping for something that would be very hard to do, at least right now. If it makes you feel any better, it is unlikely that you ethnic group will be persecuted in the States, as it is unlikely that we would come to blows. It is more likely that the U.S. would intervene in the defense of Armenia either in part or by proxy if it was invaded by Iran, in much the same way as we would defend other hill tribes against our rivals, like the Kurds.
I'm of "Presidents should do what they promise" decent. "Presidents who EXPLICITLY promise to call something for what it is but fail to do so later" descent. It's remarkable that you think that if Obama did acknowledge the Armenian Genocide by Turkey that this would have completely fractured that bilateral relationship. The best results of acknowledging such is a) keeping a promise to do so, b) assuaging Armenians, c) objectivity re: particular state's acknowledgements.
And "Turkey as a hedge against Russia and Iran, and Syria". You're a bit overblowing things, right? Turkey uses much/most of the recent conflict to bomb Kurds. Educate yourself. Including recent Turkish election results.
And finally, it's supernaturally bizarre that you think the US acknowledging the Armenian Genocide would cause the US to lose control of the Bosphorus Strait. Or cause pillaging bands in Israel to rise, or whatever you're on about with the Levant. "The Levant"? The bias over describing that territory that way is buzzing.
Turkey is one of our ******* and reliant on us and if we declared them to have murdered millions of Armenians, they'd huff and puff but we'd still be in control of them. For as much as they may do, which so far in Syria vs. ISIS is 90% jack **** and 10% murder Kurds. Allies like that? Well **** them, if Obama has any sense of honor for millions of dead Armenians. And they'd again, still be our *****. Complain a bit but still bound.
The realpolitk reason for Obama not acknowledging this is so small that it cannot be seen by anyone other than biased Turks or biased Obama fan-bois/apologists. Which one are you?