Why are ship designs so unrealistic in scifi?
I'm a big scifi fan, and 90% of the stuff in the genre is completely fucking retarded.

Your standard scifi ship:
- Lacks thermal radiators to dissipate the excess heat generated
- Lacks some form of thrust on its "front" to slow down the ship, behaves as if there was friction on space
- Uses unrealistic FTL methods that are barely theoretically possible, if at all
- Has magical artificial gravity
- Handwaves realistic fuel/food/supply requirements
- Handwaves the effects of time dillation
- Has magical FTL communication
- Often has ridiculous aerodynamic shapes that would not be necessary in space
- Etc, etc.

Pic related, shown in Avatar of all places, is more close to what a realistic interstellar ship would look like. But it still looks somewhat limited compared to what the future may actually bring.

How could we design a realistic scifi ship that looks both futuristic and respects common sense laws of physics? Do you have better examples?