That's sort of a fallacious argument though because you could say the same thing about every part of a spacecraft that is used only for the return phase of its

That's sort of a fallacious argument though because you could say the same thing about every part of a spacecraft that is used only for the return phase of its mission. It might be more accurate to say that the ratio of mass for re-entry equipment to the entire craft mass is too great. But with that said I think that the ultimate failure of the shuttle was that the design wasn't amenable to low cost maintenance. A spacecraft could have a crappy payload to orbit as long as it's cheap to maintain and use with quick turnaround. I have a feeling that should Starship succeed this will be the case with it and it will end up having a substantially lower payload than intended but will make up for it with a design that's cheap to build and maintain.