I think an argument can be made that the betting rule is overly broad, especially in this day and age where bookies are pretty much a thing of the past and everyone in the current athletes' generation is only betting thru online apps. I seriously doubt that a college athlete betting thru FanDuel on the FIFA World Cup, for example, is going to get into any serious debt, have any sort of inside info, etc.
However, because I'm also a firm believer in the Law of the Slippery Slope, I do tend to agree with the NCAA's stand that rather than making a whole bunch of different loopholes in the rules, it's just easier and more efficient to say that one of the rules for being a college athlete is no betting on sports, period.
I do not subscribe to any of the arguments being made concerning "nanny state" or "they're adults", etc. We all in our lifetimes become part of organizations (schools, businesses, etc) that have a certain level of requirements (dress codes, NDAs, etc) to be part of them. No one is forcing anything, the gov't certainly isn't requiring anything, and we're all free to leave those associations if they place an undue burden or requirement on the things we value or think are important.