I fully understand why logging is disabled. What I am just pointing out is that the numbers that you see are probably not indicative of a framework's production performance. I realize that logging does add another variable to the mix but in my opinion, it is something worth knowing as it gives an idea of the actual performance of a framework. And on the contrary, I find that logging impacts performance noticeably depending on the implementation and granularity. I also think that cleaning up the logs on server shutdown should be fairly trivial. However, there are the cons you also listed that's quite a compelling argument for disabled logging.
As for sessions, I just used Yesod as an example but it applies to all frameworks and other "middleware" as well and this is something I am mixed on. Some platforms do not support any middleware at all so should these also be classified as "stripped" or "barebones" also? What I'm getting at is, is this really a fair comparison? From a glance on the benchmark page, it is not apparent which frameworks have which configuration or feature if you're not familiar with the framework itself and it can get really complicated. I think labeling the frameworks in terms of size is a huge step in the right direction but my belief is that more information is needed.
The real lesson is: if you can write your app in a much faster framework with equivalent development speed, why even waste time to write it in Rails.