Oh I understand the problems of addiction. Trusssttt me. As a long-time Utopia player, I have a dubious need to login every 6-8 hours (at most) to cast protection spells and put troops in training.
At a 5x reduced speed, however, buildings that take 10 minutes to build now will take nearly an hour. That means I have to login once an hour to develop at peak speeds. That gives an immesurable edge to people who spend time logged in and doing little more than idling, which will in turn cause the less-active (or those weak enough to need sleep. Sleep, psh.) players to lose every time, because they couldn't build more than one structure at a time.
With these speeds I can accomplish a lot with an hour of playing and feel good about leaving the game to rest. With an improved build queue system that has no/less penalties attached, I can set it to build and go to bed, waking up in the morning 8 hours later to find I've successfully kept pace with the rest of the world.
Of course, that brings about other problems I distinctly remember from Utopia...But not quite so many.