I would have agreed with this, but the permissions they ask for are pretty benign and clearly relevant to their mission.
I couldn't find a way to sign up and exclude private repos or organizations.
And yes it's a GitHub limitation, we request some limited readonly access and no code access (we don't need it).
How is that not a problem imposed by Percy?
I'd feel more comfortable having a different mechanism to request an invite.
While the permissions don't grant Code Access, it does ask to read Organization and Team membership. I'd expose data for every member of my companies github organization to Percy, JUST for an invite.
However:
Sign up for Service != Sign up for Invite.