Which increases airspeed unless they have more flaps, air brakes, or put it into a slip, not the things you want to do if you need power to adjust.
Airports will need longer runways to account for the increased risk of missing the touchdown zone due to the shorter window for adjustments in a steeper glideslope.
Elevation comes into play. There are already certain airlines that won't fly direct into high elevation airports such as Mexico City due to the runway distance needed for a high-elevation airport. They're not going to accept a steeper glideslope.
Agree