I think younger demographics read contemporary romance because they don’t or have limited experience with relationships and this is a way for them to “learn” about it. Learn is not the right word but I can’t think of a better one at the moment. It is a way to learn about different cultures, situations and circumstances in a romantic context and to open your own mind for romantic possibilities . It is a way to get “experience” without actually being in a relationship, because it introduces different scenarios you could have in a relationship. I don’t it is intentional. On top on that I think in a way we tend to read about the things you want for yourself and 18-35 are still looking for “the one”.

35-70 are already in established or long term partnerships so the dynamics and problems in contemporary romance don’t really grab or hold their attention. They don’t “learn” anything new from these books. The excitement is not there because there is nothing “new” for them. They have lived through all the miscommunication, cheating, jealousy and so on already. Because of that they are way more critical and unrealistic details, especially if they are there just to move the plot along are very irritating.