Because it is expensive and time-consuming. Here the admins devote some time but no headaches. We all benefit from Chicken doing this as a job, with all the attendant issues. Sure, the domain name is $13, but that's the cheapest, least stressful part of the whole thing.
Actually, if someone else buys the name I could probably find time in the day to create the website in a couple months. I can see it now: tAggyArk, the new website with all of your aggie news and views including updates by tmc, columns by Tbird, and member posted stories FREE.
The appeal of this community is having the SECRant, Recruiting board, MSB, the OT, etc all in one place with actual traffic. But when we want to talk Aggie Sports, it's right here. A board on it's own would take a lot of work or it would die from lack of traffic imo.
I was actually serious about buying the domain, but a lot would have to happen to make setting up an entire site worthwhile