Most of those benchmarks are against Perl 5.8, the version of Perl released in 2002. 5.10 had major regexp engine improvements, and 5.12 had minor improvements. Anything is fast when you compare it to 10 years ago.
Furthermore the 5.8 engine is pretty much the 5.6 engine, which was significantly slower than the 5.005 engine. Why the slow-down? Because 5.6 has logic to check when regular expressions are matching slowly, and then to add tracing when it is. This makes many of the exponential slowdowns that Mastering Regular Expressions describes be automatically caught and handled fairly quickly.
The CL-PCRE and Java regular expression engines don't have those somewhat expensive checks, and so are much more likely to encounter catastrophic behavior.
Yeah, but who cares about real-world code if you have a neat benchmark page? Most of your "users" will never even get to the point of using your package -- after saying how great it is on Reddit, they'll turn on their porn and forget all about it.
I actually ran my own tests to see the difference, including tests against hash speed and so forth. But it is good to know there are other benchmarks out there that correlate with what I found, even if older ones. Has anyone published new ones?
The CL-PCRE and Java regular expression engines don't have those somewhat expensive checks, and so are much more likely to encounter catastrophic behavior.