I don't mind onions when they're used as a real ingredient. French onion soup, stir-fry, onion rings, all good. Onions also make decent filler in soup and curry, but I think the only soup I've had without onion is cheese & broccoli. Every ground meat I've seen uses onions as filler, so every burger, nearly every taco, most sausages, every lasagna, every spring roll, all have that onion taste.

If leeks were used like this, I'd probably hate them too.