Why don't typical US colleges offer more online courses? [closed]

I think there are multiple reasons, I'll touch on some:

• Currently online courses tend to fill a gap for students who otherwise would not be able to complete many courses.
        This allows non-traditional students to have a chance at academically being competitive, although traditional students sometimes utilize them as well. They aren't designed to replace traditional courses, but to augment them.
• It's harder to verify who is actually doing the coursework. 
       This seems like a fairly important issue, after all, you want potential employers to be confident that the degree a university bestowed means something - namely that you earned it. As a university, you want to be sure that your students aren't cheating.
• Market saturation.
        In-line with the previous bullet point, if classes were very cheap for many students, universities wouldn't be able to charge as much in general per student. This essentially translates to a lower value "per degree". This effectively tackles you point about joining "reputable" universities - the general train of thought is "If everyone can get in... is it necessarily reputable?" (Definitely a con from the university's point-of-view as they can potentially inflate their importance by limiting degrees conferred.)
• Points of failure.
        An online class, depending on the format, could potentially require a large amount of bandwidth. This means the university would be footing the bill to effectively run these courses, and the facilities to run quality web-based courses may not be cheap. While it's true the lectures could just be recorded or utilize some sort of learning software, decreased student interaction tends to lead to lower grades overall (Source: multi-year TA)
• Decreased profit.
       Arguably, I believe colleges make a fair amount of money by physically having the students on campus. "Butts-in-seats" mean that they charge more longterm for dormitories and food. Increased physically facility usage allows colleges to approach benefactors for more money, citing student use and need of expansion. Benefactors want a dorm with their name on it, not a server rack.
• Collaboration.
       Not the bad kind, mind you. Like @WetLabStudent mentioned, physically being at a college or university exposes you to ideals, people, and methodologies you might have never come in contact with. The ability to interact with a large spectrum of people is an important skill for the vast majority of students to develop.

This isn't an exhaustive list, but I hope it raises some of the issues. If I missed a few more major relevant points, feel free to comment.