DeathStrobe, you hit upon the crux of the matter: officialdom and fandom.
Officially, Haesslich is/was a Great Dragon. Therefore, officially, he is (or was) a Great Dragon; period, full stop.
Fandom, on the other hand (and me amongst them) gets divided into two camps on this: Great or Not Great? The wiki articles, I have no doubt, had edit wars over this very thing, and it boils down to one question that the fans try to answer:
Could a Vindicator Minigun LMG kill Haesslich?
There are issues with answering either way on this, of course. "Yes, it could." Then this makes Haesslich either a) the single most dumb-ass stupid Great Dragon out there, because you had
better not think that when Aden came off Ararat and punked Tehran into the New Dark Ages, the Iranians just sat there and let him do it; see Ghostwalker's first arrival in Denver (Year of the Comet) for exactly what a Great Dragon on a city-wide rampage is going to be doing, and you can bet that Iranian fighter jets and tanks and jeeps with pintle mounts were all going to be trying to engage him, which really doesn't jive with what we know by three examples (Aden, Ghostwalker, and Sirrurg in Aztlan) a Great Dragon can do; or b) Haesslich simply didn't
possess that level of competence and power, which means that he wasn't a Great Dragon, and the official statement of 'he was a Great Dragon' is wrong.
But officially,
he was a Great Dragon. That means he
must have possessed somewhere around the same sort of level of competence and power as Aden, Ghostwalker, Sirrurg - hell, even the newest-of-newbie-Great-Dragons, Masaru, can take on several of the world's superpowers (i.e. Japanacorps) in essentially an extended war
and win. So then the answer has to be "No, it couldn't." Which means that, well, Haesslich has been laying low for most of three decades - probably because all the other Great Dragons, and even a lot of adult dragons, are snickering up their sleeves when he shows up at dragon parties saying, "Hi guys!! Guess what happened to me today!!" So he's embarrassed, and pouting in his room. Or hey, maybe he's just catching up on his reading and stock manipulation, y'know?
The real problem, of course, comes - came - down to the out-of-world situation: the early writers did not have a really solid grasp of the game, and Predator had just come out with its cool minigun 'look, I chop down JUNGLES for fun' scene, so they figured, 'hey, yeah, sure a minigun is going to punch through dragon armor.' You know - if a single frickin' arrow can kill Smaug, imagine him facing heavy autofire!! It might possibly be the single most glaring failure-of-concept issue in the early years of the game. And because Shadowrun is essentially a persistently-developing world over the last going-on-three decades, it becomes a legacy point of irritation.
Or a point of plot. Watch your back, shoot straight, conserve ammo, and ....