I can see why you'd say that that way but the author probably feels that way because of the domain they work in. I've encountered research types who just use bi

I can see why you'd say that that way but the author probably feels that way because of the domain they work in. I've encountered research types who just use bigint everywhere because it's safer and they don't worry about the perf. When I was coming up as a game programmer no one would use boost shared_ptr and weak_ptr because of perceived issues with it. Everyone rolled their own handle system. In fact there were a lot of people that considered languages beside C/C++ untouchable due to perf. They couldn't fathom there were domains where that perf just wasn't that important. I now work a lot with Unity and find people feel the same about C# foreach because it used to trigger an allocation. You'll find people often make the mistake of thinking their domain specific problem is a problem for everyone.