Yes, that is exactly what I mean. See, when you have a real tight sight picture (i.e. no light on either side), you will "know" exactly how to line up your sights to make a shot. The problem with that setup is that:
1) The gun will move anyway,so you'll never have that perfect SP
2) Once your tight SP is off, you cannot tell how far it is off/where the bullet will go
3) It takes more time to get the desired sight picture
A wider SP will give you faster information of where the bullet will go. It may seem inaccurate at first, though.