I suppose it's an ethical dilemma if you believe human cells are somehow special in the universe. If you're a materialist who just believes we're advanced animals then why object?

The only thing that concerns me are health related issues. We've been eating animal meat for tens of thousands of years and it is generally recognized as safe. Sure, there are obvious health issues, and even the occasional prion disease or parasite, but basically we know the risks and, in the "first world" anyway, we mitigate them. It seems that the consumption of human flesh has caused issues in the past due to prion diseases. If we're confident there isn't a path where the prions could infect the lab meat, or we test for it, then "eat up" as far as I'm concerned.