Honest question: do you have a real-world example that indicates that the extra pointers added due to multiple inheritance actually results in performance degradation due to extra cache pressure?
I concur with the description of the Delphi implementation, as I've navigated it numerous times myself. I guess I don't understand the author's negative tone with regard to the C++/Delphi implementation. There's going to be overhead with any choice made and C++ and Delphi made the choice to sacrifice memory usage for speed. Furthermore, the only part that really scales with the number of objects is the extra vtable pointer for each implemented interface in each newly constructed object. Hardly a significant overhead in today's memory-prolific computing environment. Also, pointer fixup thunks and unconditional jumps are easy to speculatively handle.
I think it's important to understand that while everyone has conscious and unconscious biases, it's not true that recognizing that fact is the same as assigning blame. The idea is to better know one's self, to try and understand one's own bias (to the best of one's ability, that is) in order to try and apply correctives when making decisions involving people who are different than we are.
It's when we actively press into these biases that we hold and steadfastly cling to them in the face of contrary evidence that we become guilty.
Now I'm not claiming that having bias is a good thing, it's quite the opposite. I am saying, however, that having bias does not imply culpability.