The main issue is that there isn't any governance to the plugin store. Once you have a plugin in there, you have free reign to do whatever you want with it. Getting it in there is a PITA though. For example, a library author and I created a plugin, but they wouldn't let me submit it because I wasn't the other author, and they wouldn't let him submit it because he wasn't me. True story.
TBF there is some scrutiny on existing plugins, the team is just extremely understaffed (it’s ran by volunteers after all). I got involved in a plugin that ended up getting de-listed for some minor ToS violations after several years of being “fine”, they re-reviewed the plugin with the same rigor as a new submission.
Kudos to these volunteers, but as long as one single company continues to insist on owning all the resources of the plugin and theme directories, I don't think they deserve to continue profiting from volunteer labor.
