I suspect no one wants to build on this corner because it's full of loud nightclubs (Nest/Den, El Rancho, Sneaky Dee's, etc), drug dealers and has a murder or attempted murder every 6-12 months. There are lots of properties ~300m away from here that are much harder to build on because of existing use (new condo near college and spadina, proposal on the car rental lot, Silver Dollar room site, etc) but it seems like no one wants to touch this disaster of an intersection. If the land had the same value as the entertainment district you'd probably see some progress but it only supports development <10 stories (my guess). If the city stopped the serving of alcohol after-hours and enforced it's own noise by-laws in this area you'd see 2 of 4 the corners get developed.