Very good observation. More to the point though, rather than them "investing" in internet realestate, they should be "embracing" any expansion of the internet space. Because by its nature the growing internet - desktop first, laptop next, and now mobile - all help expand awareness, knowledge, discussion, and hopefully vetting of any and all areas of interest.
Another possibility is that academics can often be myopic, so knowledgeable and focused on their area of study, and frankly too busy or uninterested to venture out of their niche. Don't get me wrong, I absolutely respect, admire, and appreciate their years of effort (often lifetimes of effort). Everyone should be so fortunate - to find their passion and niche in life as many professors and other intellectuals do.
But being a risk-taking entrepreneur is very different than living under the safety-net of academia. Living with fierce competition, making a payroll, working at getting and keeping customers, cutting budgets, etc. in the business world is foreign to academia. Contrast that with rich endowments or tuitions and budgets that increase at multiples of actual inflation.
The "free" use of their .edu email accounts, campus-wide wifi/broadband, and use of subdomains under the college's .edu domain have all help set the blinders to the adoption and use of other possible domain extensions.
Ultimately, the students will bring .mobi to the campus world.
-acc