How can there be so many major issues on one home?

I'm not the only one with issues. I've talked to many people at different complexes and not one person was happy with the construction of their home 

These are only some of issues. You would be spending hours if I posted everything, it's that bad!  

Plywood along stucco on left side not nailed at all. Only a small section of the outside wall was removed and found not built to building code standards

Structural damage due to water penetration causing mold & wood rot

Improperly framed wall, note light coming through 2 x 4s

Plans call out continuous Simpson ties at top and bottom of all studs - Not done

Mold and wood rot caused by water entering through improperly installed expansion joint

Floor out of level - fixed numerous times trying to level it. Issue we believe is wet rafters used, building code violation

Soffit pitched at an 8 degree downward angle to the stucco from the fascia allows water to backside of stucco

Rust on metal corner bead

Water dripping in from water test

Mold on stud by window and lentil. I have mold and wood rot all over