See: qa-base.php (qa_load_plugin_files())
$pluginfiles=glob(QA_PLUGIN_DIR.'*/qa-plugin.php');
glob() makes plugin-name-array in order of folder name. An order is manipulated after this line. I explain to slight degree for those who cannot understand the necessity for this feature.
This feature exist always in many systems. This feature prevents problem related in plugin execution order. What is problem related in plugin execution order? Yes, It is related to program which action by concept of "inheritance" / "override" of "Object Oriented Programing".
Example1 (Override function):
Many functions of Q2A are overrided. For example, theme customization is realized by overriding function of qa-theme-base.php. When there is two or more plugin which carries out the override of same function, result changes by the execution sequence of plugin.
Example2 (CSS decoration):
The definition in which the ornament in CSS appeared behind excels pre definition. When there is two or more plugin which ornaments the same HTML tag, result changes by the execution sequence of plugin.