Can you justifiably say something is shit not just from a subjective point of view?

Have you guys seen 2001 a space odyessy?
Well first of all …don’t. Its terrible.
But it like one of those movies that people tell you you just HAVE to watch… because its a cult classic or something
I was trying to argue against a colleague, with me saying that it was shit…. or at least frustrating to watch…. and she keeps saying things like like ‘oh maybe you just didn’t understand it’
Sorry….have you seen the movie?
No?
Well then shut up.

Its 2 hrs 29 mins long … and its slow as hell.. and its one of those kind of movies where you know that it was made for people on drugs.. like LSD or something,  but if you’re not on LSD… its pretty fucking terrible.
And like a good boy, I of course don’t want to give away too much… of why it IS terrible, but now I’m getting insulted because of a predetermination for which she thinks the movie is good because she’s seen some reviews online.

Bah!
Reviews are for idiots!
Why is it that the simple reviews are never taken seriously?
ie.-  Its shit, don’t watch it.
Wait sorry, let me change my review. It’s shit because….. (people always want to know the because) it’s slow, its full of extended 15 minute scenes for which we already got the point in 2 mins, and unless you’re on LSD, I would not recommend this movie.

Perfect!

Here’s a friend’s review for the film…and its more like a watching guide:

Imagine a movie written by a director who thinks he’s being deep enough to create a cult following on his film. Imagine the beginning of time when monkeys roamed the planet, now a plot twist. A rectangle black rock. It appears throughout the film for zero fucking reason. Fast forward time and they will talk about deep space and bush babies. Fast forward for 15 minutes or nauseating coloured lens flares and crappy sound. Black rectangle is seen. The end.

By the way, for those that haven’t seen the film, here’s a little insight…. The first word, the first bit of dialogue is spoken after a full 26 mins.  Before that you’re just watching monkeys behave curiously.
Come on!

Note- I will concede the movie is full of some pretty basic science-fiction concepts that has fuelled ideas to shows that we all know and love, (like Futurama for instance) and of course it was pretty impressive for when it was made, 1968. You will see that I said ‘impressive’, impressive doesn’t necessarily mean good.

By the way… In terms of movies that are designed to be watched when you’re as high as a kite, I think ‘Gravity’, ‘The life of Pi’, ‘This is the end’, ‘Pineapple express’ are the ones that I know of….anyone got any others？