Earlier quoted context omitted.
> Spending non trivial time on lowering memory consumption from 40 to 28 MB in case of normal end user desktop applicaton is not reasonable in the sense that very few users will care or even notice. This hides a big problem of today’s software. Instead of having time to actually think about their software and optimise it, it’s all about throughput and making the economists happy. That’s why projects use various ready…
economists happy? I'd argue it's just normal business incentives
Applying this to the original question one gets that if performance ceases to increase users can no longer be expected to endlessly ramp up their specs so suddenly optimisation and slimming-down will be in vogue.