Without going onto the rights and wrongs of this, it is worth noting that some years ago (1970's and 1980's I think), this actually ended up with court cases re. the canoeists and anglers in Matlock Bath. There had been punches thrown, lines allegedly cut by canoeists, and certainly one angler deliberately trod on the deck of a canoe and wrecked it. The canoeists had a slalom course on the river, one of the few places where a river in Derbyshire was suitable, but it was also a favourite fishing spot and the anglers were bitterly antagonistic. The anglers tried to prevent canoeists parking in the riverside car parks and it all got really nasty and the dispute regularly made the local press for several years
The East Midlands Sports Council became involved at the time and tried to mediate but without any apparent success. However it has been quiet for many years now and the issue hasn't made the local papers since pre-2000. I did wonder if this had anything to do with the setting up of an artificial canoe slalom course at Holme Pierrepont in Nottingham around the same time as the aggro in Matlock seems to have died out - it gave the canoeists an international standard variable slalom course to play on and a very considerable amount of money was spent on developing the facility by the Sports Council.
However, this only satisfies the specialists and keen competition canoeists who have to pay to use the Holme Pierrepont facility. Maybe people who simply wanted to paddle down the river were put off and don't bother with Matlock any more.
Having canoed down the River Wye a few times with no problems whatsoever, it seems to be one of the few rivers in England which is both suitable for canoeing and must have a right of navigation and is also a fishing river where the fisherman have to co-exist with the canoeists. It's also the border between England and Wales for a good part of its length where it is suitable for canoeing. It's regularly used for commercial canoeing holidays with standard camp sites along the banks but this only seems to apply downstream from Hay-on-Wye and it is a pretty wide river for most of this lower length so easy to avoid bank-side fishermen.
Some rivers do have a right of navigation but they are the larger rivers, such as the Thames, the Trent and also, of course, places like the Norfolk Broads, where there are also fishermen but they seem to co-exist OK with canoeists.
Whilst I have every sympathy with canoeists, I'd be wary of siding with anyone in this dispute because so much of it is about money spent on fishing rights and the huge income potential for landowners with suitable fishing rivers on their land. The canoeists are going up against big money here.