Yes it matters for your first job, but not after that. So if you have a low GPA you may have to take a crummy first job, build some experience and use that to show you deserve the better job.
To turn it around, imagine you are looking at two resumes from people with nothing but a degree, one with GPA of 2.7 and the other with 3.65 -- which would you ask to come in for an interview?
When I was reading resumes to hire [software] developers at my old employer, the ranking was high overall GPA, then high discipline GPA, then low GPA. However, low GPA + some good internships might win out over high GPA with no experience.