GPA. Important? Yes and no.
Firstly, GPA does not correlate to intelligence.
A lot of very intelligent students are bored or "unchallenged" by course work and therefore get lazy and stop trying. Look at Einstein.
Anyway, if you're applying to an airline that requires a college degree and you don't have much of a work history, what else can they do but look at your GPA as some measure of your study habits? After all, they don't want to spend all the time and money on your training only to find out you can't study and retain information.
I'd never make a quick judgment of a person based solely on their GPA but it does happen. So I'd recommend trying to raise it in college.
If your GPA prevents you from admission into the college of your choice, you might need to compromise and attend a community college for a couple of years. Earn a higher GPA and then transfer your credits to a university.
Like I said, your GPA really doesn't say much about you as a person, but if you have a high one it will open many more doors in terms of scholarships and internships--which will help you get better jobs--and more importantly NETWORK!!!
Remember, it's not WHAT you know. It's WHO you know. Networking is critical especially when you don't have much work experience.
I highly recommend working on your GPA and getting involved in extra-curricular activities.
Good luck.