I've only read the summaries too but I think what it's saying is that if you choose abstinence out of fear or obligation then you won't enjoy it because it's not really what you want to do and the choice won't last. It seems to offer a different way of approaching it is which is to ask "Will I be happier by quitting?". Then, if you're open when figuring this out and in coming to your decision, you'll see that it is your happier option.
This makes sense to me because if you're quitting for happiness you need to explore if you are happier making this change and, once you see that you are, then you will be happy in your new life. From you're above post, it seems to me you have done this exploration very well
