He did it to make it get fixed faster. Think, what's going to get fixed faster: an exploit that, as far as the GSP knows, only one person knows (but many more people might be exploiting it), or an exploit that everyone knows, and the GSP knows everyone knows? Sure, it might not be the most ethically sound (grey-hat), but garry doesn't care and it really didn't break anything.
It's not about fixing it faster, it caused a kneejerk reaction by most GSP's (they had no choice) ruining the modding community. Now we're at the point where BMRF is the only one providing enough access to developers to get anything done and we're completely full now. It has done NOTHING positive and NOTHING has been fixed.
It's not his fault that they didn't set their servers up right in the first place. Create a user only for running the server and chroot them to the server directory (or whatever the equivalent is on windows, though Rust has linux builds and they should really be using those). They can't touch anything but the server and any other files in that directory. If they bothered to set their servers up right in the first place, this would've been a non-issue.
This part is true, it's not his fault GSPs haven't been sandboxing properly.
No, it doesn't.
Edited:
If you're still at a point in your life where you judge people on what they like to do, you're not really at a point where you can judge what someone else does.
I definitely can, and most certainly will judge him for his actions, and anyone is free to judge me on mine. Being a secondlife playing furry is most definitely a red flag in my book.
He asked me for a development server, I shot him down, his kind has no place in development communities, all he did was halt 90% of modding work being done when he had the chance to do it the proper way. All he has caused is grief. What he did was not constructive in any way, shape or form.
Edited:
What's your excuse for bringing unrelated furry drama shit onto Facepunch when the situation is already handled (this exploit is already known, according to Ideal-Hosting)? Stop being a concern troll.
If by handled you mean the modding scene mostly halted then yes.