I do not understand how to use that code, can you explain me what problem will this resolve? As I read it, this will remove the action that allows to deactivate the plugin, so how will people deactivate it if they do not want to use it anymore? Would not it be better if the admin user restrict the management of the plugin(s) using WordPress roles?
This plugin is for clients who absolutely want to be ‘admin’.
Later – when they change their minds – this mu plugin can be deleted by (for example) a webmaster.
Maybe this is not for independent clients without a webmaster.
I use it on sites with ‘admin’ client.
I see, it make sense in the scenario that you mention, but I prefer to keep the plugin as it is without block its deactivation because there may be users that could not understand the meaning of that. I am the only one at Sucuri providing free support in the WordPress forums (the rest of the team provides support only to premium clients).
Adding this to the plugin would translate to an increment in the number of tickets of people asking how to deactivate the plugin, some of them may be angry too, so I prefer to keep it simple and avoid misunderstandings.
Anyway, thanks for the suggestion, and by the way, you have an interesting project in that repository, I checked some of the plugins that you have there, keep it up.
