also, the hate was mostly because I'd heard so many good things about it, and i got all psyched up, and I plowed through the rulebooks, and played the first game, and then I just sort of realized "this is not actually a good game, or story, and these pieces are a kind of crappy looking, and the terrifying tyranid menace is kind of blah (thats the race I wanted to play). It was just... surprisingly dissapointing. I wanted so much for it to be as good as everyone said it was, and I just couldn't see what was so great about it. It's not really bad. It's even good. It just seems awfully... mediocre, for the fervor it seems to illicit in people.
The setting is to taste which is why I didn't dive down anyone's throat for not liking it. I grew up with WHFB, and 40k, so it's pretty ingrained in my psyche.
Tyranids used to be cooler looking until they revamped the whole model set to look more cartoony.
And the reason people like 40k is because it allows them to get into a world where it's ok to hate everyone else. Seriously. That's the major appeal of 40k. As humans you're allowed to have an unreasonable hatred of everyone. As Chaos, you get to be the cackling evil toady bent on universal destruction. As Eldar, you get to think everyone is inferior. As orks, you get to be A-political while still shooting everyone in the face. As Necrons, you don't even have to make noise...The flavor text implies it, but the fiction makes it utterly clear...the 40k universe is morally gray. Nothing is true, everything is permitted. There's an inherent appeal in that, even if in meta sometimes the game uses too many spikes, too many Space Marines and too much GRIMDARK.
I could disagree with a lot of your interpretations, but you're a brand new player and I've been playing or enjoying the franchise for over a decade now. So refuting stuff like "it's not a good story, not a good game...." is pretty much a pointless exercise. There's volumes on 40k that you don't know, but there's no real point in trying to convince someone their gut reaction is misguided. The models have gotten cartoonier, and the game continually gets more expensive to play. Those are my only real gripes with 40k. Personally, I love the Imperium backstory. I also don't know what the current core rule books read like, but I do remember I enjoyed reading every revision less. Between 2nd and 3rd ed of 40k is where I found the flavor the best. Now it seems like GWS is continually trying to streamline their world and their rules and it's having a detrimental impact on the game and the flavor. Tau. Blah.
If you don't like at least a little cheese with your setting, GWS games are never going to be for you. The game is NOT fun IMO if you don't have some attachment to the setting. The reason I enjoy Space Marines (and yes, I play Blood Angels, and no, I'm not overweight) is because I enjoy watching heavily armed zealots running out to die in the name of their Corpse God. If I didn't like the setting, I probably would have never continued paying attention to the game.
Also, 4+ player battles on epic terrain is damn fun, and where the game really shines. The standard 1v1 on a dinner table is where the game falls flatest. (For 40k anyways.)
And I guess in the end, because I've played over 5 core games using GWS's basic rule system...I find it all generally works, specific mechanics aside. And I'll say without hesitation, if you've played a game of Mordheim and don't think it's a good game, you don't know what good gaming is.