ARPGs are incredibly popular, but that doesn't mean they'll suit everyone. If you're looking for something where there's any kind of variation in the gameplay, they're not really for you. As Raze said, the entire point of them is to kill stuff so you gain power & equipment to go out and kill more stuff.
I've played enough of them myself to know that I like them when I'm in the mood, but they'll never be my favourite type of game.
The popularity of ARPGs did lead to a massive decline in games companies making true RPGs - not least, I suspect, because ARPGs need a LOT less work by game developers and will make them at least as much money.
It's only when The Witcher and Dragon Age came along that the true RPG is starting to re-emerge. A trend I very much hope will continue
