Just one more (because I like you unreservedly)

I'm posting far too much regarding Lionel Shriver lately, but it's my bat and my ball so...
But I'd love someone to explain to me why dislike for characters in a novel can lead to a negative review.
"A resolutely unromantic writer, Shriver has created a choice between two men so flawed I had trouble warming to either."
WTF?
Why would a resolutely unromantic writer such as Shriver create a choice between flawless men? Why would anyone?
Some variance on "I just didn't like the characters" doesn't belong in a proper review.
I hear this fairly often from some readers and I'll never understand it.
I wonder if romantic comedies or political campaigns are to blame, but how did we get to a point where likability determines a plausible or engaging character?
We heard over and over how George W Bush was the guy, rather than Al Gore or John Kerry; that America wanted to grab a beer with and therefore he's the leader of the free world.
How's that working out?
Surely, there's a reason why Hamlet, a complex character worthy of limitless critical interpretation; is the gold standard. But a preferred guest at the barbecue?
For novelists, creating wholly likable characters would be more of a stylistic prison than any worry to do with presentation or arrangement of a narrative. I can't imagine anyone writing a book for an audience over eight years old worrying about it.
Crime writers would laugh at such a conceit and outside of the romance genre, I'd wager most novelists would.
Critics have pointed out that the book is longish and the structure of the novel works for some and not others. Fair enough, but characters as fully fleshed out as Ramsay and Lawrence,
(the two main male characters) are going to have some qualities that are less than heroic. That's why there are novels are written for adults.

Posted by Dave