What makes you assume run-of-the-mill admin at a CC are paid well, or better?
Anyway, as far as the school is concerned, they can survive without a robust or effective CS department, but they can't survive without the admin, which is true. It takes a lot of work to run a college, and CS profs aren't the ones who do that.
Paying more to better CS profs doesn't make financial sense, because they're not going to yield more students as a result. So they'd be dumping more money on a teacher to teach the same number of students. And no matter what they could pay them, it wouldn't be enough to offset what they could make in industry.
Anyway, as far as the school is concerned, they can survive without a robust or effective CS department, but they can't survive without the admin, which is true. It takes a lot of work to run a college, and CS profs aren't the ones who do that.
Paying more to better CS profs doesn't make financial sense, because they're not going to yield more students as a result. So they'd be dumping more money on a teacher to teach the same number of students. And no matter what they could pay them, it wouldn't be enough to offset what they could make in industry.