Although all this point you have made has been said repeatedly often in this board, but nevertheless this (option A) being the "set time limits" is a good strategy for self control, but hence people still gamble above the expected amount they budget, and it's mostly caused by addiction. Aside that, most of the option you said are true. But difficult to handled.
Actually The OP made a very good point but still people don't want to stick to their limits. They always gamble beyond their budget which is coursing them more losses and addiction in gambling. as a good gambler is always necessary to have a self control in gambling. Because gambling is not something to rely on, it's essential to always gamble with what you can afford to lose.
Yes, so the conclusion is not because such gamblers do not know what is best for them to do but because they always find it difficult to do or implement various actions as suggested by the OP above and this is also one of the illustrations of why many addicted gamblers find it difficult to accept advice from others even though it is all for their own good.
In my opinion, when a gambler is trapped in the wrong mindset, it will be very difficult for them to change their approach to a better direction, the only way is to change their perspective first on gambling, but of course it usually takes a long time, one of the scenarios that can make them aware is by experiencing a really significant downturn.