I don't think it hurts to try and develop an accent as close as possible to the native accent. That's what I try and do (I said 'try'). However, I don't think that a language learner should feel disappointed if they can't achieve that. I see many students on these forums who talk as if they have failed if they can't master the accent and I see that as unnecessary. For me the main aim when I try learning another language is to master the ability to talk to someone in that language, and if I can do that with a reasonable accent then that's even better.