Some of these structures may simply be unsuitable for a large section of users given  BIS Review 102/2010  5  (v)  The responsibility for assessment of customer suitability and appropriateness is squarely on the market maker. There are a detailed set of requirements that the market maker needs to fulfil in this regard while selling any product to a user.
As the recent experience in many countries shows, inappropriate understanding of complex derivatives by the buyers of these can have serious repercussions. The argument of caveat emptor does not really work in practice, as many countries are realising on account of huge derivative losses.