Since Geany does not have a written set of rules for github usage it can be difficult for new contributors. Geany is a totally volunteer project, people do what they _want_ to do if they have time and ability. There isn't a cadre of paid programmers who are looking for the next thing to do, so most statistical things that are useful on corporate sponsored projects are unused here.
And having lots of people adding +1 to things has in the past annoyed people more than encouraged them.