Again, it it comes back to trying to regulate so that one cannot make a mistake, but it still happens to everyone. Even running a dedicated Part 95 approved radio for GMRS, grabbing the wrong mic and using the wrong call sign. The reason many of the newer Chinese radios over lock the firmware (only 1 repeater channel possible for each repeater frequency) is to keep you from using the radio outside of GMRS.
Once you get away from CCRs and into real LMR equipment, you begin to see the benefit of zones and other features. MURS has no use to me, so I don't ever even listen, but I do listen to railroad while traveling. Zones can let you split up frequencies by location/service/etc. Build separate zones for GMRS and ham, then when you are scanning the zone, you only respond to ham or GMRS. My Harris radio will go even further, by holding multiple mission plans (on the fly changing of code plugs). I have 1 for amateur radio (with zones for each group of counties in the entire state), and 1 for work frequencies. Can't ever mix them up then, even with a bump of a button.
I have issues with many of the cheap chinese radios and their performance overall. While technically just as wrong, using proper LMR radios with Part 90 certifications is less of a concern when used on GMRS. They technically meet all the performance criteria of Part 95, where as the CCR radios are a huge crap shoot if it meets, they just toss a different firmware and sticker on the radio. I know some meet specs, and they may have gotten better over the last few years, but after my experiences with front end overload of expensive CCRs, I've determined it's not worth the cost savings to deal with a marginal receiver (and possible out of spec radio), not to mention the other plusses of true LMR equipment.