That tells me why it sucks from the perspective of a compiler writer in 2017. But it doesn't tell me if it sucked in 1979 in an era when ask was much more frequently hand-written and there were many more physical constraints and trade-offs. x86 seems often to be judged by later innovations like RISC. But that wasn't a thing in 1979 and sucks for hand-writing anyway - perhaps you want more complex and non-orthogonal instructions in 1979.