So why was predator 2 so shit?

You know... having the dubious pleasure of being able to watch Predator 2 again I am reminded just why it was so dire. I made my initial opinion with the mind of a child but any hope that I'd view it differently with the mind of an adult didn't last long. I mean... you can see what they intended. But what they intended and what we got, are two very different things.
Observe:

Well firstly... Danny Glover. I have nothing against Danny Glover. But we're coming fresh from a film that saw Ahnold go toe to toe with the Predator and only win because he managed to drop a huge log on the Predator's head. And I mean that literally, he didn't shit on him, he dropped a massive log crushing the Predator's unprotected skull. And even then the Predator was able to activate his self-destruct and laugh as Ahnold fled 'to da choppa!'. Danny Glover wouldn't stand a cat in hell's chance against the Predator. Hell, when Batman fought him (and remember Batman has tons of gadgets and was trained by mountain ninjas) he ended up in a coma for weeks. Ok so that was the comic books and not canon. But still.
Right from the start Danny Glover's character jars with me. His insane car stunt makes no sense. By rights he should have had his face shot off right there. His rulebreaking gets him repeatedly bollocked yet everyone seems to let him get away with it. Even when he enters Keye's trailer at the end Keyes puts up no resistance, letting him in on the whole story immediately. And why didn't the predator just fucking shoot glover in the initial rooftop scene? He's armed and aiming straight at him!
Which brings me on to the Predator's behaviour. What the fuck is he doing in the city? Why is he killing criminals from rival drug gangs, going so far as to target the leader of the Jamaican Voodoo Posse? It makes no sense. Which is why Ahnold refused to reprise his role as Dutch and why we got stuck with Glover. We see the Predator's code of honour again when he spots that Leona is pregnant on his thermal vision. We never find out what all that was about. Apparently it was cut from the film. O_O So why leave the pregnancy reveal in?
It gets worse! Just as things finally start to pick up and Keyes and his men try to trap the Predator by using body insulation and UV light we finally get to see the Predator's other vision modes. Great! Then we see him blast Keyes with his shoulder gun only for Keyes to get back up a short while later and take another shot at him! Now ok, we do know that the Predator cannon can stun as well as kill. It happened in the first film although we're not sure why. But here Predator is killing Keyes' men one by one. Why spare Keyes with a stun blast? Doesn't make sense.
We also see Glover cut off the Predator's arm after he initiates his self destruct which seems to completely nullify its effect. Why? Is the wrist device just a timer? Is the explosive within the body of the Predator itself?
Also, the Predator is clearly able to learn human speech and mimic it in context. In the first film we see him memorize Mac's line "Turn around" which he whispers in Dillon's ear as he's stood behind him. He also memorizes Billy's laugh which he performs after setting his self-destruct. In this film, he utters the line "Shit happens" showing a clear understanding of humour. If learning language is so easy for a Predator then why does this one only have a couple of phrases uttered by the immediate cast? He's been hunting presumably for some time. I forget exactly how long Keyes says they've been tracking him but it's long enough that he should have a bigger selection of language.
And what about the other Preds?! There's like ten more on the ship. What have they been up to this whole time? If there were ten predators in the city surely we would have heard about it.
And the ship!! Why does it have three inches of fog on the floor? In the film Alien that was explained. The alien eggs need cool temperatures and the ship they were on had a cooling system that maintained that floor mist. Surely that is not something the Predators would want! After all, there's an alien skull among their possessions. Clearly they are already hunting them. Giving them a perfect environment to live on on your own ship seems stupid.

Oh and also... why does the Predator save that guy's necklace, only to return it to Glover later? Is that supposed to be significant somehow?

Then there's the shooting. Predator is shot multiple times in the film. Pretty much every shot ricochets off his armour. Expect of course when Glover shoots him near the end, somehow hitting his soft underbelly with each shot. Now in Predator 1, the Pred is new to Earth so his lack of body armour is understandable. But why the second Predator seems to think he can wear chest armour and leave his abdomen exposed is bizarre. I mean, he knows about guns. Even the Predator in the first film recognised guns as a weapon and the second Predator can even differentiate between a real gun and a toy. He has a ship full of equipment. Why no full body armour?

And finally. The (sonic?) chakram. I'm guessing the lights on it and the sound it makes are meant to indicate it has some form of sonic technology. That would certainly explain how it cuts through a handful of animal corpses and the entire body of Gary Busey. But even then I'm struggling to see how Glover has the strength to nearly rend the Predator in twain near the end. Even with one arm the Predator should have dodged and then gutted Glover like a fish.

Oh and with regard to production values in general... Why the obvious green screen on the ship at the end?

Sigh. It was all just so... pants, really. That's the only word I think can fully describe how disappointing the film is. It's pants.