Ari nailed it but I'd like to add that many designers, while trying to do their own thing, often make grave errors. Important factors are simply glanced over or others deemed "not important". Ari says we are crazy to run our amps on such high voltage rails (and he's right) but that's a better approach than RSA with the A-10, "who listens that loud?". Then we have the flipside where a design is supposed to be this and that regardless of how it will sound. No better example of that than then the EC Electra.
The bottom line though is any designer must have a good idea what the end result should be regardless of what is being designed.