[fish_fan]

Well, butter is a well-defined substance; there's a reason why "I can't believe it's not butter" isn't called "better butter".

Furthermore margarine is associated with health risks that butter is not; clean is just disingenuous.

[nkoren]

Fair enough, but margarine is not a good analogy to in-vitro meat. It's a substance that has very little molecular resemblance to butter. In-vitro meat, however, is meat. It's not a different substance -- it's just produced in a different way.

[overcast]

Yes, but margarine isn't butter, this lab grown meat is actually the same product. You're comparing a substitute, to a replacement.