Probably because it's much smaller with less "bloat". No addon support, much smaller, proprietary, no advanced settings (or any at all). Just Webkit with a search bar. (So basically just bullshit).
I need a benchmark for how fast a browser allows me to mindlessly reopen the same bookmark(s) even though I just closed the tab(s). That’s my most common task in Firefox.
Phoronix has always had a strong editorial bias. No mention that Firefox has recently caught up on Speedometer 3 or the other benchmarks Firefox is faster than Chrome in.