Why do you need permission to modifiy an add-on?
The purpose of Add-ons is the ability to modify and share it.
The need of so called "permission" is the reason why so many add-ons are private.
>>>It is done here too.<<<
This permission thing is the same as no-pix-no-clix.
Whether the modified add-on is good or not is another issue.
Now you are a failure.
How would you feel that you make a (eventually) good [insertitemhere] in your life, then someone takes it from you, changes a tiny bit of it then releases it to the
world community, without putting your name. The OP does not include the name at least, it only includes "credit to whoever made it".
Plus if you check the OP you see it's
EDITED.
I bet you he added that "credit" when he edited.