I think his point wasn't that sunk cost are a myth, but rather that they shouldn't make you blind to the problem of the platform you're bound to. Whether or no

I think his point wasn't that sunk cost are a myth, but rather that they shouldn't make you blind to the problem of the platform you're bound to. Whether or not that's something that happens here or elsewhere can be argued and I don't necessarily agree with him, but that's where he was going with it I believe