The market forces for producing software however... are not paying for such externalities. It's much cheaper to ship it sooner, test, and iterate than it is to plan and design for performance. Some organizations in the games industry have figured out a formula for having good performance and moving units. It's not spread evenly though.
In enterprise and consumer software there's not a lot of motivation to consider performance criteria in requirements: we tend to design for what users will tolerate and give ourselves as much wiggle room as possible... because these systems tend to be complex and we want to ship changes/features continually. Every change is a liability that can affect performance and user satisfaction. So we make sure we have enough room in our budget for an error rate.
Much different compared to designing and developing software behind closed doors until it's, "ready."