I haven't seen them either, but how can you assume it isn't a good movie if you haven't actually seen it? If you haven't experienced it you can't actually say its good or bad, thats not how it works xD
I've seen parts of then on TV over the years, never sat and watched them fully. Though I did see Jurassic World in theatres last week, which was decent. I mean if you're looking for a stellar plot and character development, the Jurassic movies are not for you. But it will always be cool go watch dinosaurs eat people. And I personally wish there had been more dinosaurs and less people in Jurassic World.
I think everyone should watch Jurassic Park. Not just because its a great film but because it has such a cultural impact that it shaped completely the way movies were made.
Jurassic World isn't, anyway