For some people, including me the value of fishing is inversely proportional to the number of people taking part at any particular place and time. Then there is a little fact that while this little lake, well tiny really, is not a secret, it has had the reputation of producing the odd trout every few years that weighed 2 or 3 lbs or more. Best I recall it had quite a population of daphnia. As did Mill Lake once and produced some nice size trout up to 3 to 5lbs back in the 60s. It's not stocked with a lot of fish, hundreds and it doesn't take much pressure to "fish it out". Some people appreciate a lake like that and prefer not too many people know about it.
Then there are people who have made a life style & even some money on providing some "fishing education" on how to and where.
These are separate paths and are to some extent mutually exclusive. Neither is right or wrong in any fundamental sense. Those on the former path understand that part of their strategy is to keep their mouths shut as well of the mouths of their friends. They also under rate their success they have and sometimes downright lie about it & the how and where. It's a code! Some get offended when others don't follow the code. Others know if they wait most of the newbies will be disappointed in how challenging it can be and disappear, possibly into an alternate universe.
In my view the Province does very little to provide much in the way of quality stillwater fishing on the lower mainland. I know a little lake not much bigger than the one featured in the video. It also was known to produce some nice trout over 2 pounds. Chubby ones at that. It hasn't been stocked for over 30 years for reasons of public safety. Odd thing is that hundreds more people swim and sun bath there come summertime than fish it spring and fall.
BTW winter fishing in the lakes of the Fraser Valley and Island is no secret and has gotten mentioned from time to time as long as i have been fishing. Most don't do it much because the fishing is often slow and the weather often cold. Fish in bigger and deeper lakes often hold off shore in deep water and are hard to reach.