But unlike Brian, those three are likable and not from some show that died out years ago.

Wanna know something funny I noticed? Nostalgia Critic, Spock, and Gandalf all died protecting others.
NC: Merged himself with the Plothole in "To Boldly Flee" and save the other ThatGuyWithTheGlasses reviewers and the universe.
Spock: Sacrifices himself to save the rest of the Enterprise crew in "Wrath of Khan".
Gandalf: Fights off the Balrog to save Frodo and the others in "Fellowship of the Ring".

Brian? He just got hit by a car. Yes, it's tragic but when you remember all of the crap Brian's done as a character, not only do you lose sympathy but when nonsense like his revival is pulled off the way it did, it still feels fucking cheap.

When NC, Spock, and Gandalf resurrected, they had things left to do. What the hell did Brian have left to do in his life? I sure can't think of anything that's worth bringing him back for, beyond wasting time and money in the process, just for a BS message about 'not taking those you love for granted". Yes, that was the message that was supposed to come out of all this.