well, I would not say that getting a ham license is trivial. It does take some studying, you need to find an exam, pay fee(s) etc. The exam is not difficult technically speaking, but it will take a few hours all together to get it all done. Certainly more time-consuming than just paying online for a GMRS license. And you can lose it all if you forget to renew. But you get more potential use out of the ham license. One of the main advantages I would think is the availability of repeaters which I imagine is better than GMRS, so better distance communication. Plus APRS, email etc. And I wonder if a ham radio is not cheaper than a comparable GMRS.
There is also MURS.
At the end of the day, though, if you're talking about trail communication, it is meaningless to discuss that without there being a consensus among the participants, whatever it is, and I suspect there will always be folks who just don't want to deal with the ham aggravation.