Ems typically have really short ball times, no score exploits, wider flipper gaps, no "modes", no ramps, and don't give crazy end of ball bonuses. It is way harder to master their shots than to learn their rulesets, as where new games are harder to learn their stupidly deep rulesets than to master the shots.
Simply put, only really pinballers, the real men and women out there, play EMs in tournaments. EMs take real finesse and skill. They don't play themselves, they have no ball saves, and definitely no chill. They're brutal and unforgiving in their simplicity.
That's why I love them, and why they need to be in every tournament in at least a 1/5 ratio of EMs to LCD era games.