This is because the Titans are otherwise portrayed as a good and life-affirming force in a considerable number of sources. We even have a hard-canon source there. (UVG) When someone like Algalon comes along, it seems more logical to me to look for an interpretation that is consistent with all the other lore, rather than to delegitimise it.
I have to admit, though, that the dialogue you posted is making it hard for me lol. I couldn’t remember it at first.
He says also this:
Algalon the Observer says: Stand back, mortals. I’m not here to fight you.
Algalon the Observer says: It is in the universe’s best interest to re-originate this planet should my analysis find systemic corruption. Do not interfere.
And I found this:
Brann Bronzebeard says: Wait a second: this doesn’t look right! Next to this blinking light… what’s this Algalon signal?
Archivum System says: Initiating query. The Algalon Failsafe is an automated emergency signal following a Prime Designate’s demise.
Brann Bronzebeard says: Prime Desigate? Where have I 'eard that before? By my grandfather’s beard, Loken is Azeroth’s Prime Designate. Loken’s death triggered this!
Archivum System says: Affirmative. Timestamp of Prime Designate Loken’s destruction coincides with signal activation.
Brann Bronzebeard says: Well? Who’s on the listening side of the signal? What’s going to happen?
Archivum System says: Searching… Destruction of Prime Designate is considered the first warning sign of systemic planetary failure. Algalon observer entity’s arrival is followed by planetary diagnostics resulting in one of two possible reply signals. Reply-code Alpha, signaling “All is well” and Reply-code Omega, signaling planetary re-origination.
Brann Bronzebeard says: Planetary re-origination? Speak plainly, ye blasted machine!
Archivum System says: The decomposition of the planet and its living organisms into base elements: metals, rocks, gases. This is followed by a period of reconstitution of each element into the original planetary blueprint.
Brann Bronzebeard says: Hear that, lads? It’s only the end of the world! Well, what are ye waiting for, ye rusty machine? Initiate Reply-code Alpha. All is well! Pints are on me!
Archivum System says: Request denied. Reply-codes built into Algalon observer entity. He is both messenger and message.
Brann Bronzebeard says: Well, what’s this Algalon going to be looking for with his diagnostics? What are our chances?
Archivum System says: Algalon diagnostics assess danger of systemic Old God corruption in planetary vital functions. Calculating chance of Omega Reply-code…
Archivum System says: Ninety-nine point nine nine percent.
Archivum System says: That’s repeating, of course.
Brann Bronzebeard says: Blast it, lads. Looks like we’ve got a fight ahead of us.
If it always follows the same principle, it looks as if there was corruption on the other planets too. Algalon acts like an emotionless AI, but one that does what it thinks is right. The raid had to defeat Algalon, but at least this kind of resistance made him realise how much the people of Azeroth value their lives. Especially when you consider this:
First enrage:
“See your world through my eyes: A universe so vast as to be immeasurable - incomprehensible even to your greatest minds.”
Turning the tables, consider what an AI in our world (irl) would have to do to avoid being destroyed if we declared it flawed.
However, it is also possible that this lore is out of date. The World Soul didn’t exist in WotLK, and Chronicle mentions Aman’thul’s motivation for creating Algalon:
“In his final act before departing, Aman’Thul commissioned the constellar Algalon the Observer to serve as the world’s celestial guardian. The possibility that the world-soul could become corrupted was one the titans could not ignore. Should that come to pass, Algalon had the power to initiate a procedure that would activate the Forge of Origination, purging the world of life and any corruption that was present.” (vol I, pg. 42)
It’s not entirely clear why this protocol should exist on other planets, especially if there are no other worldsouls.