Figurative speech is part-and-parcel of what writers do. What more powerful tool is there to describe something than to compare it to something else?
Some readers love the gratuitous use of figurative speech, other readers hate it - I tend to lean toward the latter. This isn't because I'm not a fan of a well-turned comparative phrase, it's just that there's a tendency to overuse them, quite simply because they can be so effective.
I think a well-observed and simply described detail can be worth a thousand clever similes. So when can metaphors and similes become a problem? Here's my take on it.
When they draw narrative focus to irrelevant details.
It is the writer's duty to do what the Russian Formalists called 'defamiliarization' i.e. to represent familiar things in unfamiliar ways, and figurative speech gives us an excellent opportunity to do it - but there's a difference between familiar and relevant. If our heroine is on a train going to meet her lover, do we really need to be distracted by a clever observation about suitcases in a luggage rack mating like tortoises as the trains stops? No, I don't think so either. Details can reinforce mood, strengthen the narrative, and even provide symbolism - but leave the mating suitcases at home.
When the comparison distracts from the thing it's seeking to describe.
If the comparison is actually more fascinating than the object/situation it seeks to shed light on, then in my book, it's failed. When the suitcases come together like lips smacking in a post-coital kiss - what are you actually thinking about? Chances are it's not suitcases.
When the comparison is offering no fresh insight into the thing it seeks to describe.
Water tinkled off his chin like Stuka dive-bombers unloading their bomb-bays. I'm sorry? How is this offering the reader any real, fresh look at some man's dribbly chin? For a comparison to work the things compared have to be comparable.
I think it's quite possible to fail on all above three points and still provide a witty or clever comparative phrase, and I think this is another reason why some readers can be forgiving of a metaphor or simile that doesn't make my three points. But I think this makes for superficial writing - style over substance - and I'm a firm believer in striving for both.
Try taking the three point challenge on your metaphors and similes.
(N.B. the cheesy examples here are all my own work - any familiarity to anybody else's writing is purely coincidental. Actually, I'm quite warming to the Stuka dive bombers...)