I license all software I use. In general people are not interested in licensing software so I see no point in sharing plugins for those.
You already know as long as "how to license" provided, they are added to plugins (acronis plugins, drivesnapshot, ultraiso etc.)
In general people are not interested to feedback what they found at home, that is the reason behind some plugins lack license info, and some others already have....
Many of the plugins are downloaded in the past from here and tweaked. Others I did develop myself but are not production ready or have my own license keys embedded.
you know as long as info or plugins provided, we manage them on servers in time, and update them regularly during development.
home made unshared plugins are away from such service.
In general people ignore spending time to share, than they need to update their plugins themselves at home in time....