I once contacted the author to check out my open source package and benchmark it and he mentioned that he actually charges for the benchmarking exercise. So yeah.
Consultants have a rule: "Never say No. Always say: this is how much it will cost".
It's a "no" but with a threshold.
People can elect to work on things voluntarily for personal reasons, but if someone asks them to fix or do something for them, then instead of saying no, they might say "how much will you pay me?" It's their time and they're under no obligation to offer it to you for free (though they can voluntarily choose to if they want).
His articles are extremely well documented, so there's nothing stopping anyone from performing the same benchmarks.