Hourses for courses.
Most people who criticise CB are not CB users, same for Amateur, VHF or PMR.
Then you get people who just hate radio full stop.
I have a VHF ready should I ever need it, but we tend to take CBs on the boat because I have a couple of handhelds with autosquelch. I've never heard anyone else on CB who was on a narrowboat, but I've normally been sitting on one obscure channel talking to my wife at locks or when one of us has gone ahead to look for a mooring spot. Whatever radio you use, they're extremely useful in those situations, or just for asking for a cup of tea if you can't be bothered to shout.
I guess in my ideal world there'd be a common channel for narrowboats that any canal based CBers could monitor, but getting people to agree on one would probably be impossible. At least in the 4x4 community they've got 16 as a pretty logical number to use. If anyone can think of a number between 1-40 (apart from 9 and 19) that would appeal to narrowboaters, feel free to chime in!
CB has a bit more range than PMR especially over open countryside but they're all limited when you're in close proximity to walls, bridges, locks, trees etc.
The good news is that you can't really get a better ground plane than the roof of a steel narrowboat. Sadly it's true that a lot of what you hear on 19 these days is a small local clique talking to each other day in and out about nothing. That doesn't mean that if you've got something to say and someone to say it to, CB can't be used as a perfectly good means of comms. PMR is definitely cheaper, though.
And for anyone still talking in 80s slang, no one waffles on about convoys or rubber ducks any more than they wear red specs and braces with their leather filofax - you're just showing your age.
One day I'll get round to doing my amateur license and then I'll think about some handhelds on a higher frequency but they'll never be commonly used because they cost and they're restricted to licensed operators.
edit: Don't forget that CB can now use SSB and AM legally so there's a bit more capability over the standard UK FM that we've had since the 80s
Here are some radios