Could one look at the issue as a lack of non-licensed band for use that actually works better than FRS. Seriously, if some guys wanted to go hunting once a year where radios would be good to have for safety reasons, or do more than talk across the street, FRS is just a toy.
1. Amateurs use the UHF band as well which is around 15MHz lower from FRS/GMRS frequencies. I am not aware of the amateur frequencies working better.
2. No testing is required to use GMRS, just obtain an FRN, apply for GMRS and pay the money. Usually within 24 hours the licensed is approved. A GMRS license provides one to use more watts on certain frequencies, a repeater as well as a detachable/improved antenna.
3. MURS is VHF and although limited to lower power has different characteristics. MURS radios can also use external/improved antennas.
4. Citizens Band radio uses a lower frequency and provides different characteristics.
A licensed is required, or the frequencies are licensed by rule. I am not aware of a non-licensed band, but I get your point. Also, although a license is required for amateur assigned frequencies, everyone is welcome to take the
easy test and then use radios that allow higher watts...and the many repeaters amateurs have put into place that do not require fees from fellow operators. Yes, that's right, get an amateur license and significantly extend the range of a low power handheld radio. Honestly,
if an adult using a firearm is unable to pass the technician test they are a liability more than an asset to the hobby as well as themselves and others. Still, they have the GMRS option of not taking a test, or CB, or MURS.
* As to hunters using VHF marine equipment, yeah I hear them. Still, I know some guys that previously did that. A hint of information and they obtained their amateur licenses and even GMRS licenses. They also still enjoy using the CB. What they no longer do is use marine frequencies.