I reckon there are a large number of people with an IMC who are not current and do not use the rating. Most, recognise their limitations, and whilst they might use the rating typically to cross a high overcast to fly VFR on top, not many fly hard IFR. Seems to me that unless you have the opportunity to remain current, maybe because you are in a group or have other friends with which to fly to help you remain confident, many simply do not keep up the skills after gaining the rating. Of course, the longer they leave it the more rustly they become and hopefully the more reluctant to fly in IMC. I would certainly be interested in others views also.