It was indeed unpopular at the time and not widely known now. I personally actually enjoyed the action (I think the final gunfight is one of the best or at least most fun I've ever seen), but I understand how it would be unappealing to some.

As I mentioned, Christian Bale's performance is allegedly what got him the role of Batman, so make of that what you will.

It's also worth mentioning that there are enjoyable qualities to the movie even discarding the action. If and when you do watch it, I hope you enjoy it!