NLP includes some very effective ideas and tools - but they are just that - tools. Tools can be used well or not, for good purposes or not. The tools are really quite inexpensive in and of themselves. The originally books and courses were very affordable.
NLP can and does work long-term as well as short-term depending on what it is used for and how it is used and by whom. There is a level of skill involved in using the tools if one wants to build for longevity.
The subject of addiction would be a complicated one. The effects of many drugs is not just neurological in nature. A drug can effect many systems of the body and there is the bodily addiction to be taken into consideration as well.
NLP as proposed by Robbins makes it into some sort of magic and hence can make for some unrealistic goals and promises. I believe that is what Robbins sells - not the creators of the science.
NLP is no substitution for a good diet or good lifestyle habits, but can be a useful and valuable adjunct for self-change - at least that has been my experience. Because it has been so valuable to me, I don't care very much for what Robbins has extrapolated it into personally, but generally I think he has made some of the basics more available to the masses - which might have some overall positive aspects.
Also, an nlp practitioner trained by someone like Robbins is going to be quite different than one trained by Richard Bandler. Robbins' trainees and students will have all sorts of other mumbo jumbo in the mix for sure and is perhaps part of why nlp is perceived as such these days by so many. Totally understandable. It's like when you say that I am into eating raw foods these days it's all mixed in with everything that raw vegans often put into the mix. Raw vegan raw foodism is more widely known - just like Robbins is more widely known. I've never considered raw food to be one in the same with everything it gets lumped in with and I do not see nlp as the same as all that it gets lumped into with either.
Raw foods and nlp are both very useful strategies - if come to with a little basic intelligence and logic that is. Both can get a bit of religiosity attached to them by some followers though. That's always a danger with humans.