It is great that these services focus on helping plugin authors resolve support requests which is a non-trivial part of the ranking and completely under the control of the plugin author (unlike active installs).

There are two things I see that they don't seem to be highlighting:

If the plugin tested version is more than one release out of date then the score starts reducing exponentially. Two versions out of date reduces the score by 12%.
If the plugin is not translated, then it mostly won't rank in non-English search results. English words do match, but the scoring is multiplied by 0.00001. There are a lot of services out there that provide translation.