I'm withholding my own judgement on that.
For anyone curious, the authors are coming up with a code quality score using an open-source tool called SoftWipe[0]. From the paper:
> SoftWipe is an open source tool and benchmark to assess, rate, and review scientific software written in C or C++ with respect to coding standard adherence. The coding standard adherence is assessed using a set of static and dynamic code analysers such as Lizard (https://github.com/terryyin/lizard) or the Clang address sanitiser (https: //clang.llvm.org/). It returns a score between 0 (low adherence) and 10 (good adherence). In order to simplify our experimental setup, we excluded the compilation warnings, which require a difficult to automate compilation of the assessed software, from the analysis using the --exclude-compilation option.