Is there such a thing as a lemon bike?

I had my bike for 6 month now (a KHS 3 speed cruiser). I ride it every day to work. Some spokes broke a few weeks back. Next my coaster brakes was stuttering - they told me the brake pads were misaligned. Now I just got it back and I feel a slight vibration in the pedals (only when engaging the pedals).

The irony is I got the bike because I figured coaster brake/3 speed IGH would be low maintenance.