I can understand the love for chaos. I can understand the respect for the Eldar's epic last stand. I even, to an extent get why people like Orks, being so built for war that their technology literally only works because of the belief it ought to work. But I cannot understand why anybody would actually LIKE the Tyranids.
This isn't about the perspective of game mechanics or what have you - all the armies are routes to the same end and common game mechanics ensure that Tyranids don't really get to have the overwhelming strength in numbers they should presumably have, it's about the race itself.
There is nothing about the Tyranids to latch on to. There is no inherent humanity present, there is no single minded love of warfare, there is no religious crusade or even a desperate battle against inevitibility. All you have is a singular conciousness of unfathomable intelligence that is seemingly bent on a single goal: reproduction. The Tyranids are not in a fight for survival or ideals, they simply exist to propogate their species, and they are frighteningly effecient at it. You have an enemy that literally cannot be stopped - once a planet has been attacked by the swarm heroics and firepower will at best serve to delay the inevitable. One way or another, when the tyranids attack the only thing left on the planet will be ash or tyranids. It is literally an insurmountable force, whose motivations are so utterly alien that they defy all attempts to categorize.
In terms of their actual tactics, I cannot imagine a more loathsome enemy. When facing the legions of the Guard, no matter how great their strength in numbers or their weight in firepower, all you have at the end of the day is a group of men with flack jackets rifles and bayonetts. One knows the limits of human endurance, one knows the limits of human engineering, and where there is at least a modicum of knowledge there is a route to victory. Tyranids on the other hand represent a complete unknown, a force that literally evolvs the biological weaponry best suited to fight a given foe in a given place. All you can know for certain is that a single tyranid, little more than a horrid amalgamation nighmare fuel and fangs is mortal and can be killed. But the true fear lies in the fact that killing a single tyranid or hundreds or even millions is irrelevent. Unless the corpse is utterly annihilated it will simply be reabsorbed into the swarm, and it's compatriots will fight on just as fiercely. Standing against a tyranid invasion is to stand against the very horrors of the subconcious. No matter what company a soldier keeps, no matter what race bore him into the universe, to fight against the swarm pits a soldier against his worst fears, and such battles are always fought alone.
Tyranids are, quite simply, the literal incarnation of the worst monsters of the imagination. The boogeyman in the clost is a Lictor waiting to pounce, that unknown noise in the distance at night signles the coming of a carnifex. How anyone can sympathize with what amounts to fear itself is quite beyond me.
