I think anyone who has tried any weightloss groups where you get on the scales and get applauded if you have lost 4lb in one week has the mentality that they should be losing weight as quickly as possible.
When I think about diets that I've tried before the main effort was sustaining them for long enough to make a big difference. This way of eating feels different - I don't have to deprive myself for months on end, I just have to be really strict for a couple of days. I can see me keeping this up for a year, more if need be.
If I can lose weight whilst still allowing myself to have wine / chocolate / take aways / anything I fancy then I'd rather do that and lose less than a pound a week than do something far more restrictive that I can't keep up. If I can manage a lb a week I could be half a stone lighter by the end of May, which is massively inspiring for me as it's probably the difference between fitting into my smaller sized summer clothes in the loft!