Critics loved Drive. Ebert (and others) gave Die Hard a great review (if you read it, instead of just looking at the star quotient). People that say that sort of stuff probably don't know what they're talking about and are trying to justify the fact that they like bad movies without having any idea "what makes it bad."
"I like it" does not make something good. That's a big hurdle for a lot of people.
I completely agree.
I look at critical consensus as a great quick-glance to determine whether a movie is worth my time. I'm familiar enough with the scoring system that I know what to expect... and frankly, I generally agree with the scores.
On Metacritic, 90+ means it's a critically beloved film... something approaching masterpiece and very likely an Oscar Contender.
80-90 - Outstanding film. One of the year's best.
70-80 - Great film. Most people will enjoy it.
60-70 - Good film. Unless you hate the genre, it should be fine.
50-60 - Mediocre, but if you like the genre you should enjoy it
40-50 - Avoid these movies unless it's a genre you love
30-40 - Probably garbage, but if it's your favorite genre you might be ok with it.
20-30 - "The Love Guru" starring Mike Meyers
Still, I have the capacity to enjoy most movies on that scale. The most recent "Hobbit" film scored a 58. It wasn't a very good movie, but I was fine with it, because I like the world.
"Divergent" scored a 48. Not a good film, but if you're a big fan of teenage "Hunger Games" style angsty action movies, you'll probably be ok with it. My girlfriend works with teenage girls... this was right in their wheelhouse. I liked "Maze Runner" slightly more. Not surprisingly, it scored slightly higher (56).
Both "Dumb and Dumber To" and "Hot Tub Time Machine 2" scored below 40. Garbage movies, but I love comedy so I enjoyed them for what they were.
A lot of fans get super defensive when critics dislike their favorite movie. I happened to really like "Man of Steel" (55), because I love Superman... but I fully understand why it scored that low. I agree with the score.
On the flip side, I HATE the Horror genre. I'd rather get punched in the face than sit through a Horror movie that scored under 60 on Metacritic. I reluctantly went to the theater to see "Cabin in the Woods" with my girlfriend mainly because it scored a 72. It was a really solid movie. I enjoyed it. The quality of the film outweighed my major dislike of the genre.