I can't believe I am actually needing to retype this, but learning to speak with an American Accent is important to me, to us [a group of friend]. From my own experience, if any native English speaker hears you say any sentence, or even just a few words in English, they will immediately know you are not a native speaker. People may understand what you are saying and they probably won’t laugh at you to your face, but they certainly notice it.
This shouldn't be considered a “bad” thing, but in our modern and competitive society, speaking English closer to the way native English speakers speak will give you many unfair advantages in life. People who go and study English in the US or Canada will have much better job opportunities when they return to their home countries than people who do not leave. A lot of this reason is the pronunciation they learned makes the person sound “richer”, more “educated”, and more “international”. This is even true if the person didn't attend a good school. Just having a nice sounding accent and good pronunciation in English really helps both your personal image and your opportunities.
Learning English in America gives students huge advantages, not only with better paying job opportunities, but even in social situations like dating. They seem to get more respect in society from both westerners AND people from their own country. It’s not “fair” but it’s truly the way it is. We all need to accept the way the world actually is, because even though it’s not fair, it’s impossible to change it in our short lifetimes. What is the point of hiding our head in the sand and pretending this isn't true? It makes much more sense to understand how the world is and do something about it that will benefit you.
So, if you want to know why you even should BOTHER learning an American accent, you need to think about what most people in the world already believe and how you can use their beliefs to your own advantage in life.