Aren't most penalties generally accepted?
About the only time defensive penalties aren't is if the offense managed a good play anyway (like offsides or Def. PI)
Offensive penalties are almost always accepted unless the play would result 4th down, or put the offense in a bad down and distance (3rd & 20 is usually more desirable than 2nd & 30 because it takes away one more down while leaving them in a horrible distance).