Eyup...because they cost less.
With job depression affecting education as much as any job, community colleges are able to get a lot of great teachers who need jobs. You get Phd's actually teaching the classes vs. grad student teachers at the big university teaching the core 1st and 2nd year courses.
You get the basic freshmen and sophomore classes done at a community college and then move on to the more costly state university to graduate. You get the same state university degree and you save a lot of money. It looks good on your resume as it shows commitment, planning, financial sense and motivation that employers will find attractive.
Community colleges have more flexible class schedules so if you need to work (or ski) you can do that, putting away money for the higher cost state school.
Not a bad idea but also not great for everyone. I think at_nyc nailed it in saying that community colleges aren't necessarily good for kids with little to no direction. They'd be better served by having access to the full spectrum of degrees and courses from the very beginning so they can better figure out what they want to major in.
Where I went to college (in a large state university that was affordable at the time, just as you suggested), business degrees were part of a separate school that you had to apply separately to by the end of your freshman or sophomore year. I believe there were other degrees and sub-schools like that, too. So if you went to community college and realized that you wanted to pursue a business degree at the flagship state university, you'd be out of luck or end up having to go to school longer, which obviously isn't saving you any money.