Benchmarks are easily abused, misused, and misinterpreted. E.g., benchmarks looking at some very specific aspect of query performance being extrapolated to more complex/real-world queries.

Also trade-offs are rarely mentioned in benchmark numbers– e.g., great write throughput, at the expense of: ?.

It's fun to be cynical about stuff like this, but it's rarely as simple as "Ellison didn't react well to that and decided to forbid benchmarks".