I think to be honest to be truly assured of long term success, you do need to adopt the approach that it is a way of life and not a "diet". But equally, because it is designed to become a way of life, it does allow for those moments where you do indulge yourself.
I completely understand where Emsie is coming from - when you have lived a very different lifestyle and had complete freedom over what you ate, the fact that we made bad and indulgent choices, was still our choice and our freedom to do that, whereas when you are following a plan like SW and you KNOW that it is a great way to stay healthy and fit and lose weight long term, you can feel a little restricted by the fact that you are following a plan and are not doing that of your own volition.
Because that way of thinking doesnt necessarily come naturally, if it did, we wouldnt be following a plan in the first place or have cause to do so. I have a friend, her weight never changes from one year to the next, and she without thinking chooses healthy options, cooks healthy meals, and has the occasional indulgence without worrying about it because 99% of the time she is eating sensibly. Whereas I dont have that natural ability to just do that without thinking. Without thinking, I would dive headfirst into a big pile of chocolate and bury myself so deep that I wouldnt find myself for hours. I wouldnt automatically head for the superfree when looking for something to grab and go. So you DO have to have it within your conscious thinking all of the time.
I hope that in time, because I do this all the time, it will bury myself in my subconscious and I wont have to think about it every time I put my hand to something, I will just know what to do with it without having to go "Ah, thats not on plan" or "Ah, I already had my syns today". It might happen, it might not, but if it doesnt, then the preferable option is to have it in your conscious thoughts and not to just head down the path of total freedom and bad choices.