There seems to be similar trend when it comes to dating scams. Fraudsters are targeting them because they tend to have accumulated more wealth. They might also be a little easier to fool since they are new to this aspect of the web and don't realize the risks. They also come from a generally more trusting, less cynical age group.
Whatever the reasons for this there's at least one online dating site that has identified this phenomenon and has made preventing scams an integral part of its functionality.