The Scotch has been heavily analyzed for two hundred years or more, and most of the resulting positions have been found to be equal without much prospect of further complex play. Kasparov revitalized the variation 3.d4 exd 4.Nxd4 Nf6 5.Nc3 Bb4 6.Nxc6 bxc6 7.e5 and the Scotch regained popularity for several years. After those variations were more fully understood, interest reverted back to the Lopez and more recently the Giuoco Pianissimo. Both tend to characterized by lengthy jockeying for position before embarking on tactics. In fact, this is often how opening fashions evolve. Popular variations are heavily analyzed for tactical resources. Usually, good answers are eventually found and interest shifts elsewhere. At the moment, the Scotch is going through a quiet period. Although this could change, it is quite possible that the Scotch attempts to grab the advantage too soon.
The Lopez and the Pianissimo do not try for a quick advantage, unless Black does something daring themselves. They try for a small advantage in space and/or better placed pieces.