“C”'s will indeed get you a degree at most colleges. But most large companies and some small companies have hard cutoffs at 3.0 to interview and to hire. And the other part is that 3.0 might be a cutoff, but the majority of candidates you will be competing against will have something like a 3.3 or better.
So, you say it doesn’t matter after your first job!!! Well, my wife, with over 25 years of experience, was changing jobs and had to submit her college transcript as part of her application. They were checking for a degree sure, but they told her they were also checking her GPA; just to make sure they were getting a quality person.
If you are getting such low grades, why are you not learning the material? This will be your career and if you want to be good at it, you better know your stuff.