Fair. I get your point. My only contention is of the magnitude - imo someone 10 times better than the average developer is a unicorn. But the term gets thrown around any time someone is 'just' really good; they wrote fairly optimal code, quickly. However, to your point, there may be an argument to be made that people who have made a huge impact on the CS landscape are 10x-ers (regardless of efficiency). Is Linus a 10x-er?