It is CPU but whatever it will stay this way, I don't know. It seems to me that system of IDENA is somewhat fixed. It has capacity limits all over the place, except general cap on supply, so I guess it is designed to maintain somewhat steady flow of newly mined coins to participants of the network. This is, in fact a main purpose of this project, to present a basic income idea. Is it a good idea? I don't think so but it may be a good time to at least try so we can be sure, on what the results of such experiment will be. You would have to ask this question to developer, I would also be interested in his answer.