Slobs have always been the reason for land owners closing off access. It's just that First Nations didn't patrol their land at one time, and now they do because they have more backing from the government.
However, I've always been amazed at how our municipalities have not valued the money that anglers bring into the community. If you go south of the border you will find many well organized boat launch sites on most bigger rivers. And, even the smaller rivers have cement launch sites and flush toilets. That is not the case in British Columbia. Most of the few access points that we actually do have are small and very rough. The Fraser is a HUGE river and yet there are only a handful of boat launches on its entire length. There are NO proper boat launch sites on ANY river on Vancouver Island. The two fishing communities of Uclulet and Tofino only have ONE very small boat launch site each... and no public parking. The Stamp river has only two boat launch sites and both are small, rough and far apart. The Cowichan River has none, and the one egress point at the brink of Skutz Falls to take out rafts is VERY dangerous in medium to high water. I can rave on and on about this situation but the municipalities don't care. Even our Provincial and Canadian Parks departments don't seem to want anglers anywhere near our waterways.