I'd probably have to agree with you if what you're claiming was true; but I believe both the Scriptures and history supply sufficient evidence to show that Christ did return during the lifetime of that generation (Mt 24:34), just as he promised. The problem is the assumptions that most people make about the nature of his coming don't align with what the Scriptures teach, which leads people to assume that his coming hasn't yet taken place. With that being said, if you're interested in understanding how Christ's return was fulfilled during that generation, I'd recommend reading the responses I provided to the initial comment on this thread.