Some people need to like the MC, yes.
And they don't seem to change their mind just because the writing is good or the situation is original.
Me, I need consistent characters that have believable actions. I can put up with a lot of plot contrivances if the characters are well-written and their motivations make sense. The minute characters behave just to advance the plot or create unearned conflict, it's enough to make me drop the story. I do not expect the ending will have a satisfying payoff, so I usually don't finish. It's a kind of deus ex machina, when characters behave in ways that are convenient for the plot to happen.
Since that's subjective, I'll put it under the same "feeling" as the MC being "unlikeable". They have been written in a way I don't like. I can't state everything I don't like in advance, but it's obvious when I see it.
POV characters need flaws and blindspots (handicaps). Most make mistakes, reveal their prejudices, and need to grow as human beings. In every coming of age story the POV character may be oblivious to how they treat others (but the reader sees around it) – that's not the same as "unlikable". Unlikable implies they have no moral compass and no path to redemption or personality growth at all.
Likable vs Relatable
When we can relate to a character, we give them more leeway on likability.
A villain with a believable motive is going to be a "better" character than an antagonist who exists just to antagonize. But, when the villain's motive is more believable than the hero's – or he is more psychologically nuanced, it undermines reader sympathy. The villain does all the emotional heavy-lifting while the hero is just a foil who floats through the events unchanged.
A different problem happens when a protagonist is too psychologically nuanced. When we can relate to a protagonist, we see their flaws and understand their reasoning, we will forgive some of their indiscretions. But, relatability is not universal. The further you go, the fewer readers will be able to relate – and the character is already unlikable, so it's definitely possible to alienate the reader.
Anecdote: My husband and I watched a melodramatic Bette Davis movie where she was caught between a jealous husband and a controlling lover. At the end my husband said he hated it because "there were no likable characters" (which is valid). But as we discussed it, there was a whole story-level that he had missed because he couldn't relate to her character at all. He didn't understand her flaws or her predicament, so he didn't understand the story was about a complicated character who compounds bad decisions in an amoral world. Had the MC been a detective in a noir movie (under similar circumstances) I believe my husband would have related just fine, and forgiven the un-likable protagonist.
Likability is objective. Hero saves the cat, and is kind to Grandma.
Relatability is subjective. If I can't relate to emo guy who must kill because reasons, I'm just never going to care whether this character lives or dies or accomplishes his goals.