Why a max number of registered sites?

Re: https://premium.wpmudev.org/wp-admin/profile.php?page=vidapi

We currently allow each WPMU DEV Premium user to register up to 20 domains. In the future we may allow more to be purchased for an additional fee.

Re: https://premium.wpmudev.org/wp-admin/profile.php?page=ustapi

We currently allow each WPMU DEV Premium user to register up to 10 sites. In the future we may allow more to be purchased for an additional fee.

Is registering domains at this page ONLY for the video embedding and Anti-Splog plugins or for other purposes as well? For example, can I use all other plugins except video embed (max 20) and anti-splog (max 10) on an unlimited number of my other sites and client sites, including WPMU DEV updates and other purposes?

Thank you.