I'm not suggesting you don't "get it" because you are thick or that you have to be an expert. Loads of perfectly inteligent and well rounded individuals will not like or "get" this film. I don't "get" a lot of films because they don't appeal to me. Lots of people love Lord of the Rings. I hate it and find it to be interminably dull. I don't "get" wizards and dwarves and a massive plot hole at the end of a 9-hour epic.
I would not call those films "shit" though just because they are not to my taste.
Also, the Coen brothers have been making films in a similar vein since 1984 - 8 years before Tarantino made his first feature. If anything you could say Reservior Dogs felt like someone tried to make a Coen brothers movie but failed miserably. Or I could complain that I didn't like the Lord of the Rings because it felt like someone was trying to make a Harry Potter film but failed miserably.
You say it was a disappointment, so presumably you had some expectations about it, was it recommended by someone or what? Did you go out of your way to watch it or catch it on TV?
This film sits in the ground somewhere between Fargo and the Big Lebowski and more light-hearted Coen films like the Ladykillers or Raising Arizona. Almost all of these share similar themes and elements - kidnap, extortion, violence, a MacGuffin and several characters that are complete idiots. A great combo. Tarantino films use most of the above as well, so I suppose the comparison is not ridiculous. There's just less absurd humour in his stuff and a lot of it is pastiche/homage.