Diary games aren’t gen­er­al­ly fun. This is part of why in a com­mer­cial mar­ket, you’re not nec­es­sar­i­ly going to see them. In fact, they’re very rarely fun at all. Some are. But usu­al­ly that’s because of a per­son get­ting into it, get­ting into the mechan­ics, etc. But many are active­ly unpleas­ant to play, even some of the more fun ones.